Laser shaping of glass sheets with chamfers

Abstract

A laser system is provided for applying modification to a sheet, the laser system comprising the sheet; a first optical element having a first surface and a second surface; and a laser configured to generate a laser beam directed toward the first surface of the first optical element, the laser beam having a first beam profile. The first optical element directs the beam toward the second surface such that the beam has a second beam profile when exiting the second surface, and such that the beam having the second beam profile is directed at the sheet and applies the modification thereto. The system includes a rotary actuator configured to rotate the first optical element by a first angle. As the first optical element rotates, the second beam profile rotates relative to the first beam profile by a second angle, the second angle being at least about 1.5 times the first angle.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 752981, filed February 3, 2025, under 35 USC §119, the contents of which are used as the basis and are incorporated herein by reference in their entirety. Technical Field

[0003] The embodiments generally relate to systems and methods for forming edges in glass products using laser perforation, and methods for increasing the strength and contact angle of the formed edges. Background Technology

[0004] Glass cutting and edge finishing play a crucial role in many glass products, such as display glass and cover glass. Specifically, the right-angled edges of glass sheets are prone to breakage and are therefore typically machined into bevels or rounded corners to minimize the likelihood of breakage. Currently, non-right-angled edges are usually created using mechanical methods such as mechanical grinding and polishing. However, these methods generate glass dust and particles that must be removed through additional processing steps, including washing or chemical treatment. Furthermore, mechanical polishing of internal contours, such as hole-cutouts, is often very difficult or even impossible, and thinner sections, such as those with a thickness of approximately 200 micrometers, are often damaged during polishing. Summary of the Invention

[0005] In the various embodiments described herein, systems and methods for forming edges in glass products using laser perforation can be provided, along with methods for increasing the strength and contact angle of the formed edges. Compared to conventional cutting techniques, laser-based machining methods can improve the edge quality of the processed glass, reduce the generation of microparticles during glass processing, and increase glass processing speed.

[0006] Carbon dioxide (CO2) laser beams, Bessel beams, and filamentation techniques can be used to process glass with right-angled edges. Pulsed ultrafast lasers can be used to form pseudo-nondiffracting beams, such as Gaussian-Bessel beams (hereinafter referred to as "Bessel" beams). The glass sheet can be transparent to the wavelengths of these Bessel beams (e.g., wavelengths of approximately 515 nm, 532 nm, 800 nm, 1030 nm, and 1064 nm), thereby allowing the Bessel beam to be modified within the glass sheet to penetrate its total thickness. Bessel beams can be generated with a focal volume having a specific diameter and length, where the diameter is typically less than approximately 5 micrometers and the length is typically between approximately 1 mm and approximately 15 mm. Under these conditions, low-intensity laser light outside the focal region of the Bessel beam can pass through the glass sheet without significant absorption, but high-intensity light within the focal region is absorbed due to a nonlinear absorption process. Bessel beams can have diameters greater than about 5 micrometers, but at these larger diameters, Bessel beams typically do not have sufficient energy density to modify the glass.

[0007] The result of laser modification using a Bessel beam is that each laser emission produces damage, creating a thin line across the entire thickness of the sheet. The sheet can then be placed on a mechanical stage below the laser beam. Individual laser damage points (e.g., perforation) can be formed with one or more laser emission sessions, and the sheet can be translated laterally using the mechanical stage. After the sheet has been translated, another laser damage point can be formed with a further laser emission, allowing for a controlled spacing between the laser damage points (e.g., between approximately 1 micrometer and approximately 20 micrometers). The damage at each point connects with the previous point, thus forming a weakened damage plane in the glass sample. After perforation, when external forces are applied to the glass sheet by mechanical or thermal means (e.g., using a CO2 laser), the perforated section typically breaks off at the weakened plane with controlled edge fracture.

[0008] This article provides methods and systems for simultaneously beveling and cutting sheets using a laser beam, resulting in products with beveled or shaped edges. If the beveled part comes into contact with another object, the bevel angle reduces the likelihood of cracking or chipping due to an impact event. In many applications, maximizing the bevel angle may be desirable. This angle can be expressed as the contact angle θ. c It is the angle between the surface normal of the beveled part at the side surface and the line tangent to the beveled edge at the point where it connects with the side surface. Figure 1The example contact angle θ is shown in the figure. c1 θ c2 And refer to the following text Figure 1 The example contact angle is described in more detail. Using the methods described herein, segments can be formed from sheets, wherein the edges of said segments have increased contact angles, with a maximum possible contact angle (as defined below) of about 12.5 degrees or greater, or even 20 degrees or greater.

[0009] Angled Bessel beams can be used to produce beveled glass edges. However, angled Bessel beams can only produce chamfers with flat, faceted edges (such as C-chamfers). If a curved, non-diffractive beam (such as an Airy beam, a curved Bessel beam, a caustic beam, or another similar beam) is used instead of a straight Bessel beam, a curved damage plane can be formed in the sheet, and after the part is released, this curved damage plane can form a beveled edge profile. However, the maximum curvature that current curved Bessel beams can provide is generally limited, and Airy beams tend to experience high aberrations during non-paraxial propagation when the propagation angle is about 15 degrees or greater. In this case, using a new beam (referred to as a "caustic beam") or a curved Bessel beam can simultaneously laser cut and bevel glass sheets at contact angles of about 12.5 degrees or greater, about 15 degrees or greater, or even 20 degrees or greater. However, Airy beams, existing curved Bezier beams, angled Bezier beams, and other types of beams can be used in other embodiments, such as in cases of high contact angles (e.g., about 12.5 degrees or greater) or in other cases.

[0010] Both caustic beams and bent Bessel beams can be used to laser-perforate sheets to achieve high contact angles in the resulting chamfers. These sheets may comprise glass (e.g., glass-ceramics). In the various embodiments described herein, modifications are made to the caustic beam shaping system and / or the bent Bessel beam shaping system to achieve efficient high-angle laser beveling.

[0011] Caustic beam phase profiles can be used such that, under non-paraxial conditions, the profile is typically maintained with a finite number of aberrations. Caustic beam shaping systems can include a prism phase that can be applied to the caustic beam profile. This prism phase is configured to minimize the angle of the light rays relative to the optical axis and reduce the resolution requirements of any phase mask used to form the beam. The prism phase can be formed using physical prisms, optical elements, or other components. Caustic beam shaping systems can also include another polynomial phase configured to flatten the intensity profile of the beam along its length and improve cut performance. For example, a polynomial phase can be used, which is an additive combination of polynomials of order 0 to 5 with the transverse coordinate as a variable (e.g., aR). 5 +bR 4 +cR 3 +dR 2 +eR+f, where a, c, b, d, e, and f are constants, and R is derived from R=(x 2 +y 2 ) 0.5 The caustic beam shaping system defines the transverse direction (radial coordinates of the beam). Additionally, the caustic beam shaping system can apply a caustic beam phase to the laser beam with an intensity adjusted to a rectangular or elliptical transverse shape (rather than a circular Gaussian shape) with a flat-topped profile, thereby producing a caustic beam with significantly enhanced contrast between the main lobe and side lobes and an elliptical focal spot shape. In the case of a rectangular or elliptical transverse shape, the laser beam can define an aspect ratio at or before applying any phase. This aspect ratio can be the height of the laser beam in a plane divided by the width of the laser beam in the plane, which is orthogonal to the longitudinal direction of the laser beam. In some embodiments, the width and height of the laser beam are not equal, such that the aspect ratio is not equal to one. When these elliptical or rectangular intensity profiles are combined with a burst laser, side lobe absorption can be significantly reduced, and cracks generated during cutting can be guided parallel to the cutting direction. These modifications enable the caustic beam to cut glass or glass-ceramics with a larger contact angle of about 15 degrees or greater, or even about 20 degrees or greater. While achieving these large contact angles, it is still possible to easily and cleanly separate contour-defined sections that have been perforated within the sheet. Contour separation can be easily achieved by applying stress through mechanical bending or by applying thermal stress using an infrared laser (such as a carbon dioxide laser).

[0012] Bending Bezier beamforming systems can also achieve increased contact angles. Using certain systems described herein (such as the 4f system), two separate portions or halves of a beam can be generated, and these portions or halves can be combined to form a complete beam with a relatively symmetrical shape. Furthermore, optical retardation elements (e.g., in the form of a small piece of glass or another material) can be introduced into one half of the bending Bezier beam to move it closer to the other half, thereby avoiding a low-intensity region at the center of the bending Bezier beam. In bending Bezier beamforming systems, split quarter-wave plates can also be used to decoherently decohere the two halves of the bending Bezier beam and simultaneously shape its focal spot into an elliptical shape to control the cracking direction parallel to the cutting direction. These modifications enable the bending Bezier beam to cut glass with larger contact angles of at least about 15 degrees, at least about 20 degrees, etc., while still maintaining the ability to separate sections that have been perforated from the sheet. A split quarter-wave plate can include four quadrants, each having a fast axis that is rotated approximately 90 degrees relative to the adjacent quadrant, and the polarization of the laser beam can be circular when the laser beam enters the split quarter-wave plate.

[0013] Additionally, while most laser processing beams are rotationally symmetric about their propagation axis, several key non-diffractive beam shapes and other beam shapes remain for laser processing. For example, near-net-shape fillets and beveled edges can be achieved through a single pass of the laser beam. Furthermore, other techniques, such as angled Bessel beams, multi-segmented Bessel beams, Airy beams, bent Bessel beams, and caustic beams, can be used to create unique beam shapes. For each beam type, diffractive optics produce an asymmetric, quasi-non-diffractive beam focused into the bulk of the material. These beams can be designed to produce beveled or curved surfaces, reducing or eliminating the need for additional edge grinding to achieve the final edge shape, while also providing other potential advantages. To achieve this, the beam can be rotated and aligned relative to the edge being cut, thus achieving proper alignment. Furthermore, for complex shapes (such as circular device screens), rapid changes in orientation may be necessary to maintain rapid cutting. Current options for this include rotating the part, rotating a dimensionally adjustable portion of the optics system, or rapidly changing the beam on a moving forming element. However, the rotation of substantial parts and / or a large number of system components in an optical system is usually slow, complex, and limited by the actual manufacturing system size, and such rotation can be particularly difficult when the components are rotated more than 45 degrees.

[0014] In the various embodiments described herein, optical methods and rotatable optical components can be provided for using prisms to achieve rotation of a shaped beam. The rotatable optical components and methods can be used to generate laser beams with spatiotemporal pulse shapes to achieve features such as shaped edges with contour tangent profiles or complex aperture shapes, and these features can be produced with high productivity.

[0015] Advanced beamforming for laser processing considers novel processes, such as forming beams configured to produce C-shaped beveled edges in laser processing, and forming beams that produce pre-shaped cuts using a laser beam in Airy laser processing. One challenge with these beams is their lack of symmetry, and they typically must be rotated relative to the workpiece if they need to be used in different orientations. In the various optical methods described herein, a single rotatable optic element can be rotated. This rotatable optic element can be configured to have a compact size, making it easy to rotate due to its compact dimensions. Furthermore, rotatable optic elements can increase the rotational speed of the beam profile by two or more times, enabling faster, shorter-distance movements and improving processing speed and manufacturing efficiency.

[0016] In some embodiments, a multi-axis machining system can be provided that enables the rapid machining of complex perforations or other modifications within a sheet. Both complex external and internal profiles can be formed within the sheet. In some cases, the incident beam can be configured to have a small linear offset relative to the optical axis of a prism or another optical element, allowing the focused beam to rotate rapidly about a rotation axis within a circle while maintaining its orientation relative to the tangent of the circle. This allows for the rapid generation of internal circular features with predefined internal edge shapes within the part. In the case of generating internal features, the resulting edge shape can be positioned between a segment of the sheet and the remainder, where the internal feature forms a profile path. Ultimately, the segment can be separated from the remainder of the sheet at the profile path formed by the internal feature upon application of physical bending, thermal stress (e.g., thermal stress from a CO2 laser), chemical etching, and / or upon completion of other processes.

[0017] Ion-exchange processing can also be performed on laser-perforated sheets to enhance the edge strength and / or other properties of the sheet and any segments within it. Multiple internal edges within a large glass sheet can be laser-patterned to form one or more removable segments within the sheet, which can remain within the sheet during ion-exchange processing. The resulting perforations can serve as ion-exchange channels, thereby enhancing the contours of individual parts. Coating processes (such as black matrix printing) can also be performed before removing any segments from the sheet. After this processing, segments can be removed from other parts of the sheet. This processing can be performed more cost-effectively by further processing the sheet before removing removable segments.

[0018] One challenge in further processing sheets before removing removable sections is the potential for internal sections to "pop" after ion exchange, when these large, perforated sheets are processed downstream and accidentally flex. "Pop-up" refers to the displacement or tilting of internal parts relative to the frame of the larger sheet, causing one or more locations of the internal part to protrude above or below the plane of the surrounding frame. Such displacements can range from micrometers to hundreds of micrometers, or in extreme cases, exceed one millimeter, even causing the internal part to detach completely from the surrounding frame. Smaller perforated glass sheets (e.g., sheets smaller than approximately 300 mm × 300 mm) are less likely to pop. The pop-up challenge may be more pronounced with larger sheet sizes (e.g., length or width greater than approximately 500 mm) or with thinner sheets (e.g., thickness less than approximately 1.1 mm).

[0019] In the various embodiments described herein, the formed internal edges can create edge-locking geometry that reduces pop-out, and the removable segment may be more easily held within the sheet, allowing for ion-exchange processing and other finishing with reduced pop-out risk. For example, the internal edges can be configured with non-linear profiles and / or various complex geometries. The combination of chamfering and ion-exchange processing enables more robust large-sheet processing and, additionally, can provide final parts with essentially beveled edges requiring no subsequent machining or with reduced machining requirements. By preventing the removable segment from protruding from the plane relative to the rest of the sheet until the segment is intended to be removed, problems in downstream printing or coating processes, where a consistent surface height is typically required to ensure printing accuracy, can be avoided.

[0020] In the various embodiments described herein, a sheet having removable segments can be provided, and the sheet can be subjected to an ion-exchange process while retaining the removable segments within the sheet. Furthermore, other processing steps (such as washing and coating) can be performed before removing any removable segments from the sheet. By doing so, the processing steps of ion exchange, washing, coating, etc., can be performed more cost-effectively. Before removing the removable segments, compression zones can be formed at the inner edges via ion exchange, wherein these compression zones will completely penetrate the thickness of the sheet. Once the segments are removed, the ion-exchange material may remain present in the compression zones located at these edges.

[0021] Since popping is essentially caused by the movement of the internal removable segment relative to its surrounding frame, structured laser perforations (such as perforated chamfers) created prior to ion exchange can be used to geometrically lock the removable segment within the sheet. By forming these laser perforations prior to ion exchange processing, they can serve as effective channels during ion exchange, allowing ion exchange material to extend into the openings formed by the laser perforations. This allows the ion exchange material to diffuse at the formed internal edges, thereby allowing the formation of compression zones. This can give the segment high-strength edges. In addition to using Airy beams, caustic beams, or bent Bezier beams to form chamfers with laser perforations within larger sheets, multi-spot Gaussian beams can also effectively create these chamfers when forming them prior to the ion exchange process. Multi-spot Gaussian beams enable the formation of edge shapes that advantageously prevent popping. Chamfers created using laser-perforated multispot Gaussian beams can be formed using the techniques described in the following article: Daniel Flamm, Myriam Kaiser, Marvin Feil, Max Kahmann, Michael Lang, Jonas Kleiner, and Tim Hesse, “Protecting the edge: Ultrafast lasermodified C-shape glass edges,” Journal of Laser Applications, Vol. 34, No. 1, February 2022, which is incorporated herein by reference for all purposes.

[0022] By using laser-formed edges to secure removable segments within a sheet, segments with ion-exchanged and beveled edges can be essentially created. Beveling is generally expected to provide reliability and robustness against impacts during downstream processing. For some products, using laser-formed edges to secure removable segments within a sheet eliminates the need for post-removal mechanical polishing or beveling, thus reducing costs. However, in some embodiments, mechanical polishing and beveling can be performed after segment removal. For example, ion-exchanged and beveled segments can be lightly polished using processes such as brush polishing, removing approximately 10 to approximately 20 micrometers of material per edge. When performing minimal post-cut polishing, the resulting final segment may have a significant bevel and may have residual compression zones in the presence of ion-exchanged material. By maintaining these compression zones, edge strengths of approximately 800 MPa or higher can be achieved, allowing the segment to pass head impact tests that may be required in the automotive industry.

[0023] Beveled edges can be created using vertex distance. A beveled edge can extend between two opposite surfaces of a sheet or section, and the vertex distance is the maximum lateral distance the beveled edge extends relative to the corner where one of the opposite surfaces intersects with the beveled edge. Beveled edges can be created using vertex distances of approximately 25 micrometers or greater, approximately 30 micrometers or greater, approximately 35 micrometers or greater, approximately 40 micrometers or greater, approximately 45 micrometers or greater, or even 50 micrometers or greater. Previous processes (e.g., brush polishing right-angled edges that have already undergone the same laser perforation and ion exchange process steps) cannot automatically produce such large bevels without completely removing material that has diffused during ion exchange, resulting in reduced edge strength of the final part.

[0024] Additionally, the lasers used in the various embodiments described herein can be ultrafast lasers configured to produce perforations within the sheet at high processing speeds. The methods described herein exhibit fewer particle generation and are a high-throughput process, offering advantages over other conventional edge finishing processes.

[0025] Various products can be formed using the methods described herein. The methods described herein can be used to produce products such as instrument panel displays (ICDs) or center console displays (CSDs). By performing ion exchange processing, the resulting products can pass head impact tests, and ion exchange processing also helps eliminate cracking failures that may occur when cutting single-piece through-hole dies in multi-layered coated glass.

[0026] In one example embodiment, a method for forming a beveled edge in a sheet is provided. The method includes generating a laser beam, wherein the laser beam is a caustic laser beam or a bent Bezier beam. The method further includes directing the laser beam onto the sheet to form the beveled edge, the beveled edge connecting a first surface of the sheet and an opposite second surface of the sheet, wherein the sheet comprises glass. The beveled edge extends between the first surface and the second surface of the sheet. A first contact angle is defined between a first line perpendicular to the first surface and a second line tangent to a portion of the beveled edge immediately adjacent to the first surface. A second contact angle is defined between a third line perpendicular to the second surface and a fourth line tangent to a portion of the beveled edge immediately adjacent to the second surface. Both the first and second contact angles are at least about 12.5 degrees or greater, such that the direction of the beveled edge changes by at least about 25 degrees from the first surface to the second surface.

[0027] In some embodiments, both the first contact angle and the second contact angle can be at least about 15 degrees or greater, such that the direction of the beveled edge from the first surface to the second surface changes by at least about 30 degrees. Additionally, in some embodiments, both the first contact angle and the second contact angle can be at least about 20 degrees or greater, such that the direction of the beveled edge from the first surface to the second surface changes by at least about 40 degrees.

[0028] In some embodiments, the laser beam may be the caustic laser beam, and the method may further include guiding the laser beam through one or more elements, wherein the one or more elements are configured to apply a first phase to the laser beam in the form of a prism phase. Compared to when the first phase is not applied, the first phase may reduce the angle of the light rays within the laser beam relative to the optical axis, and / or compared to when the first phase is not applied, the first phase may reduce the resolution requirement of the phase mask. In some embodiments, the one or more elements may be configured to apply a second phase to the laser beam, and the second phase may be configured to flatten the intensity profile of the laser beam in the longitudinal direction of the laser beam compared to when the second phase is not applied.

[0029] In some embodiments, the laser beam may define an aspect ratio when or before any phase is applied. The aspect ratio is the height of the laser beam in a plane divided by the width of the laser beam in the plane. The plane may be orthogonal to the longitudinal direction of the laser beam, and the aspect ratio is not equal to one.

[0030] In some embodiments, the laser beam may be the curved Bessel beam, and the method further includes using a binary phase mask to form a first half of the laser beam, the first half being symmetrical to a second half of the laser beam. Additionally, in some embodiments, the method may further include positioning an optical retardation element relative to the curved Bessel beam such that approximately half of the curved Bessel beam passes through the optical retardation element, while the remainder of the curved Bessel beam does not pass through the optical retardation element. In some embodiments, the optical retardation element may offset the half of the curved Bessel beam relative to the remainder of the curved Bessel beam along the length of the curved Bessel beam. In some embodiments, the method may further include positioning a polarization mask relative to the curved Bessel beam. Additionally, in some embodiments, the polarization mask may comprise a segmented quarter-wave plate. In some embodiments, the segmented quarter-wave plate may comprise four quadrants, each quadrant having a fast axis rotated approximately 90 degrees relative to an adjacent quadrant. Furthermore, in some embodiments, the polarization of the laser beam may be circular when the laser beam enters the segmented quarter-wave plate.

[0031] In some embodiments, the laser beam may be generated in bursts, each of which comprises multiple pulses. Additionally, in some embodiments, each burst may comprise at least five pulses, and a time delay may be provided between each of the at least five pulses. In some embodiments, the time delay may be at least about 12 nanoseconds.

[0032] In another example embodiment, a substrate manufactured by a method may be provided. The method includes generating a laser beam, wherein the laser beam is a caustic laser beam or a bent Bezier beam. The method further includes guiding the laser beam to a sheet to form a beveled edge connecting a first surface of the sheet and an opposite second surface of the sheet, wherein the sheet comprises glass. The beveled edge extends between the first and second surfaces of the sheet. A first contact angle is defined between a first line perpendicular to the first surface and a second line tangent to a portion of the beveled edge adjacent to the first surface, and a second contact angle is defined between a third line perpendicular to the second surface and a fourth line tangent to a portion of the beveled edge adjacent to the second surface. Both the first and second contact angles are at least about 12.5 degrees or greater, such that the direction of the beveled edge changes by at least about 25 degrees from the first surface to the second surface.

[0033] In another example embodiment, a glass or glass-ceramic sheet is provided, comprising a frame and segments having a first surface and a second surface opposite to the first surface, wherein the segments are held within the frame of the sheet. The sheet also includes perforations extending from the first surface to the second surface and positioned between the segments and the frame. The segments have beveled edges adjacent to the perforations. A first contact angle is defined between a first line perpendicular to the first surface and a second line tangent to a portion of the beveled edge immediately adjacent to the first surface, and a second contact angle is defined between a third line perpendicular to the second surface and a fourth line tangent to a portion of the beveled edge immediately adjacent to the second surface. Both the first and second contact angles are at least about 12.5 degrees or greater, such that the direction of the beveled edge changes by at least about 25 degrees from the first surface to the second surface.

[0034] In some embodiments, the perforation may be formed at least partially using a caustic laser beam or a bent Bessel beam. Furthermore, in some embodiments, both the first contact angle and the second contact angle may be at least about 20 degrees or greater, such that the direction of the beveled edge changes by at least about 40 degrees from the first surface to the second surface.

[0035] In another example embodiment, a substrate is provided comprising a first surface; a second surface opposite to the first surface; and a beveled edge extending between the first surface and the second surface. A first contact angle is defined between a first line perpendicular to the first surface and a second line tangent to a portion of the beveled edge immediately adjacent to the first surface, and a second contact angle is defined between a third line perpendicular to the second surface and a fourth line tangent to a portion of the beveled edge immediately adjacent to the second surface. Both the first and second contact angles are at least about 12.5 degrees or greater, such that the direction of the beveled edge changes by at least about 25 degrees from the first surface to the second surface.

[0036] In some embodiments, the beveled edge may be formed at least partially using a caustic laser beam or a bent Bessel beam. In some embodiments, both the first contact angle and the second contact angle may be at least about 20 degrees or greater, such that the direction of the beveled edge from the first surface to the second surface changes by at least about 40 degrees.

[0037] In another example embodiment, a method for forming a beveled edge in a sheet is provided. The method includes generating a laser beam; and directing the laser beam to the sheet to form the beveled edge, wherein the beveled edge extends between a first surface and a second surface of the sheet. A first contact angle is defined between a first line perpendicular to the first surface and a second line tangent to a portion of the beveled edge immediately adjacent to the first surface, and a second contact angle is defined between a third line perpendicular to the second surface and a fourth line tangent to a portion of the beveled edge immediately adjacent to the second surface. Both the first and second contact angles are at least about 12.5 degrees or greater, such that the direction of the beveled edge changes by at least about 25 degrees from the first surface to the second surface, and the sheet comprises glass.

[0038] In some embodiments, both the first contact angle and the second contact angle may be at least about 20 degrees or greater, such that the direction of the beveled edge from the first surface to the second surface changes by at least about 40 degrees.

[0039] In another example embodiment, a laser system is provided for applying modification to a sheet. The laser system includes the sheet; a first optical element having a first surface and a second surface; and a laser configured to generate a laser beam directed toward the first surface of the first optical element, the laser beam having a first beam profile. The first optical element is configured to travel the laser beam to the second surface such that the laser beam has a second beam profile when exiting the second surface, and such that the laser beam with the second beam profile is directed at the sheet and applies modification to the sheet. The laser system also includes a rotary actuator configured to rotate the first optical element. The rotary actuator is configured to rotate the first optical element by a first angle, such that when the first optical element rotates by the first angle, the second beam profile rotates relative to the first beam profile by a second angle, and the second angle is at least about 1.5 times the first angle.

[0040] In some embodiments, the second angle may be at least about twice the first angle. Additionally, in some embodiments, the modification may be at least one of the following: cracks, refractive index modification, grooves, voids, densification, changes in chemical bonding within the sheet, melting, or color centers within the sheet. Furthermore, in some embodiments, the modification may define internal features within the sheet, and these internal features may have cross-sectional edge shapes that are symmetrical about the optical axis.

[0041] In some embodiments, the shape of the cross-sectional edge can be a curved shape, a parabolic shape, a polygonal shape, or a shape containing multiple linear segments.

[0042] In some embodiments, the laser beam can be used to form multiple internal features in the sheet.

[0043] In some embodiments, the laser system may further include a space shaping system configured to receive a laser beam to adjust the beam profile of the laser beam. Additionally, in some embodiments, a first beam profile may be formed using the space shaping system. In some embodiments, the space shaping system may include at least one of the following: a fixed diffractive optical element, a phase plate, or another optical system configured to apply a rotationally asymmetric amplitude or phase profile to the laser beam. Additionally, in some embodiments, the space shaping system includes a spatial light modulator. In some embodiments, the laser system may also include one or more preparatory optical elements configured to guide the laser beam to the space shaping system.

[0044] In some embodiments, the laser system may further include a second optical element configured to adjust the laser beam after it exits at a second surface of the first optical element. Furthermore, in some embodiments, the second optical element may be configured to focus the laser beam.

[0045] In some embodiments, the laser system may further include a polarization control element configured to adjust the polarization of the laser beam. In some embodiments, the laser beam may be an Airy beam, a caustic beam, a Bessel beam, a multi-segment beam, or a multi-spot Gaussian beam. In some embodiments, the sheet may comprise glass. In some embodiments, a first optical element may define a first optical axis, the laser beam may be received at a first surface of the first optical element at a second optical axis, and a small linear offset may exist between the first and second optical axes. In some embodiments, the laser beam may be generated in bursts, and each burst may contain multiple pulses. In some embodiments, the first optical element may be a Dove prism or a K-mirror assembly.

[0046] In another example embodiment, a method is provided for modifying a sheet to form an internal feature in the sheet. The method includes generating a laser beam and guiding the laser beam to a first optical element, the first optical element including a first surface and a second surface. The laser beam is guided to the first optical element such that it is received at the first surface with a first beam profile, exits at the second surface with a second beam profile, and is guided to the sheet after exiting the first optical element to create an internal feature in the sheet. The method further includes rotating the first optical element by a first angle while guiding the laser beam to the first optical element, thereby creating the internal feature in the sheet. When the first optical element rotates by the first angle, the second beam profile rotates by a second angle relative to the first beam profile, and the second angle is at least about 1.5 times the first angle.

[0047] In some embodiments, the method may further include adjusting the position of the sheet relative to the first optical element after the internal feature is formed; generating a second laser beam; guiding the second laser beam to the first optical element; and rotating the first optical element to generate a second internal feature in the sheet. In some embodiments, the laser beam may be an Airy beam, a caustic beam, a Bessel beam, a multi-segment beam, or a multi-spot Gaussian beam.

[0048] In another example embodiment, a modified sheet manufactured by a method is provided. The method includes generating a laser beam and guiding the laser beam to a first optical element, the first optical element including a first surface and a second surface. The laser beam is guided to the first optical element such that the laser beam is received at the first surface with a first beam profile, emitted at the second surface with a second beam profile, and guided from the second surface toward the sheet to produce an internal feature in the sheet. The method further includes rotating the first optical element by a first angle while guiding the laser beam to the first optical element, thereby producing the internal feature in the sheet. When the first optical element rotates by the first angle, the second beam profile rotates relative to the first beam profile by a second angle, and the second angle is at least about 1.5 times the first angle.

[0049] In some embodiments, the method may further include adjusting the position of the sheet relative to the first optical element after the internal feature is formed; generating a second laser beam; guiding the second laser beam to the first optical element; and rotating the first optical element to generate a second internal feature in the sheet. In some embodiments, the laser beam may be an Airy beam, a caustic beam, a Bessel beam, a multi-segment beam, or a multi-spot Gaussian beam.

[0050] In another example embodiment, a sheet is provided comprising a first surface extending in a first plane and a second surface extending in a second plane parallel to the first plane and opposite to the first surface. A first direction extends perpendicular to the first and second planes, and a second direction extends perpendicular to the first direction. The sheet also includes perforations extending between the first and second surfaces, and the perforations define sections of the sheet held within a frame of the sheet. The perforations form edges in the sheet, the edges being internal edges in the sheet, and the edges having a non-linear profile with vertices. A first corner connects the edge and the first surface, and a second corner connects the edge and the second surface. The edge extends further in the second direction at its vertices compared to the first and second corners. The sheet includes compression zones located along the first surface, the second surface, and the edges, and the compression zones are areas within the sheet where material is under compressive stress. The sheet also includes glass.

[0051] In some embodiments, the compression zone can be formed by ion exchange, wherein an ion-exchange material diffuses into the sheet to create the compression zone. In some embodiments, the compression zone can extend completely from a first surface to a second surface at one or more locations on the sheet. In some embodiments, the sheet can contain one or more coatings present on the sheet, and said one or more coatings can contain at least one of the following: ink, dielectric coating, anti-reflective layer, metal, or polymer. In some embodiments, the layer depth of the compression zone at the edge can be about 5 micrometers or greater.

[0052] In another example embodiment, a substrate is provided comprising a first surface extending in a first plane and a second surface extending in a second plane parallel to the first plane and opposite to the first surface. A first direction extends perpendicular to the first and second planes, and a second direction extends perpendicular to the first direction. The substrate also includes an edge extending between the first and second surfaces, and the edge is formed by laser-perforated holes extending from the first and second surfaces. The edge has a non-linear profile with vertices. A first corner connects the edge and the first surface, and a second corner connects the edge and the second surface. The edge extends further in the second direction at its vertices compared to the first and second corners. The substrate includes compression regions located along the first surface, the second surface, and the edge, and the compression regions are areas within the substrate where the material is under compressive stress. The substrate also includes glass.

[0053] In some embodiments, the compression zone can be formed by ion exchange, wherein an ion exchange material diffuses into the substrate to form the compression zone. In some embodiments, the ion exchange material in the compression zone may comprise potassium or sodium. In some embodiments, the surface concentration of the ion exchange material at the edge may be lower than the surface concentration of the ion exchange material at the first surface. In some embodiments, the edge may comprise a curved shape or multiple flat surfaces. In some embodiments, the edge may define a vertex distance equal to or greater than the layer depth of the compression zone at the first surface, wherein the vertex distance is the maximum distance a vertex extends in a second direction relative to a first corner.

[0054] In some embodiments, the layer depth of the compression region at the edge can be about 5 micrometers or greater. Additionally, in some embodiments, the layer depth of the compression region at the edge can be less than the layer depth of the compression region at the first surface. In some embodiments, the layer depth of the compression region at the edge may be at least about 5 micrometers smaller than the layer depth of the compression region at the first surface.

[0055] In some embodiments, the average roughness at the first surface, the second surface, or the edge may be less than or equal to 100 nanometers. In some embodiments, the substrate may also include one or more coatings present on the substrate. The one or more coatings may include at least one of the following: ink, dielectric coating, antireflective layer, metal, or polymer.

[0056] In some embodiments, a first contact angle may be defined between a first line perpendicular to the first surface and a second line tangent to a portion of the edge immediately adjacent to the first surface, and a second contact angle may be defined between a third line perpendicular to the second surface and a fourth line tangent to a portion of the edge immediately adjacent to the second surface. Both the first and second contact angles may be at least about 10 degrees or greater, such that the direction of the edge from the first surface to the second surface changes by at least about 20 degrees.

[0057] In some embodiments, both the first contact angle and the second contact angle may be at least about 12.5 degrees or greater, such that the direction of the edge from the first surface to the second surface changes by at least about 25 degrees. Alternatively, in some embodiments, both the first contact angle and the second contact angle may be at least about 20 degrees or greater, such that the direction of the edge from the first surface to the second surface changes by at least about 40 degrees.

[0058] In another example embodiment, a method for manufacturing a substrate is provided. The method includes forming a laser-perforated hole in a sheet. The laser-perforated hole defines a substrate having an edge within the sheet, and the edge is an internal edge within the sheet. The substrate defines a first surface extending in a first plane and a second surface extending in a second plane parallel to the first plane, opposite to the first surface. The edge extends between the first surface and the second surface. A first direction extends perpendicular to the first and second planes, and a second direction extends perpendicular to the first direction. The edge has a non-linear profile with vertices. A first corner connects the edge and the first surface, a second corner connects the edge and the second surface, and the edge extends further in the second direction at its vertices compared to the first and second corners. The method further includes forming a compression zone in the sheet, wherein the compression zone is positioned along the first surface, the second surface, and the edge. The method further includes releasing the substrate from other portions of the sheet. The substrate also comprises glass.

[0059] In some embodiments, the compression zone can be created by ion exchange of the sheet, wherein during ion exchange, an ion-exchange material can diffuse into the sheet to form the compression zone. Additionally, in some embodiments, laser perforation can penetrate the entire depth of the sheet. In some embodiments, the method may further include coating the sheet or substrate with one or more coatings, and said one or more coatings may comprise at least one of the following: ink, dielectric coating, anti-reflective layer, metal, or polymer. In some embodiments, the method may further include polishing the edges of the substrate, and the edges may be polished before or after the substrate is released from other portions of the sheet.

[0060] In some embodiments, the compression zone may be retained around the edge after the edge is polished. In some embodiments, the layer depth of the compression zone at the edge may be at least about 5 micrometers smaller than the layer depth of the compression zone at the first surface.

[0061] In some embodiments, a first contact angle may be defined between a first line perpendicular to the first surface and a second line tangent to a portion of the edge immediately adjacent to the first surface, and a second contact angle may be defined between a third line perpendicular to the second surface and a fourth line tangent to a portion of the edge immediately adjacent to the second surface. Both the first and second contact angles may be at least about 12.5 degrees or greater, such that the direction of the edge from the first surface to the second surface changes by at least about 25 degrees. In some embodiments, laser perforation may be formed using at least one of the following: a multi-segment angled Bessel beam profile, a caustic beam profile, an Airy beam profile, a curved Bessel beam profile, or a multi-spot Gaussian beam.

[0062] In another example embodiment, a substrate formed by a method is provided. The method includes forming a laser-perforated hole in a sheet. The laser-perforated hole defines a substrate having an edge within the sheet, and the edge is an internal edge within the sheet. The substrate defines a first surface extending in a first plane and a second surface extending in a second plane parallel to the first plane, opposite to the first surface. The edge extends between the first surface and the second surface. A first direction extends perpendicular to the first and second planes, and a second direction extends perpendicular to the first direction. The edge has a non-linear profile with vertices. A first corner connects the edge and the first surface, and a second corner connects the edge and the second surface. The edge extends further in the second direction at its vertices compared to at the first and second corners. The method also includes creating a compression zone in the sheet, wherein the compression zone is positioned along the first surface, the second surface, and the edge. The method further includes releasing the substrate from other portions of the sheet, and the substrate comprises glass.

[0063] In some embodiments, the compression zone can be created by ion exchange with the sheet. During ion exchange, the ion-exchange material can diffuse into the sheet to form the compression zone. Attached Figure Description

[0064] Now refer to the accompanying drawing, which is not necessarily drawn to scale, and in the accompanying drawing:

[0065] Figure 1 This is a schematic diagram illustrating an example optical component showing the relationship between angles in a curved beam, according to some embodiments discussed herein;

[0066] Figure 2 This is a graph illustrating objective lens numerical aperture (“NA”) values ​​according to some embodiments discussed herein, which can be used to obtain values ​​derived from... Figure 1 The optical components shown exhibit various contact angles formed at the edges, similar to those of other optical components.

[0067] Figure 3A This is an image showing an example Airy beam propagating by Fresnel diffraction, formed using a 0.4 NA ideal lens according to some embodiments discussed herein;

[0068] Figure 3B This is an image showing an example Airy beam propagating through Rayleigh-Sommerfeld (RS) diffraction, formed using a 0.4 NA ideal lens according to some embodiments discussed herein;

[0069] Figure 3CThis is an image showing an example Airy beam propagating through Fresnel diffraction, formed using a 0.8 NA ideal lens according to some embodiments discussed herein;

[0070] Figure 3D This is an image showing an example Airy beam propagating through RS diffraction, formed using a 0.8 NA ideal lens according to some embodiments discussed herein;

[0071] Figure 4A This is an image showing an example caustic beam propagating through RS diffraction, formed using a 0.8 NA ideal lens according to some embodiments discussed herein;

[0072] Figure 4B This illustrates some embodiments for generating [something] according to the discussions herein. Figure 4A A graph of the phase on a mask of a caustic beam, including two graph lines showing the phase produced when using prism phase and when not using prism phase;

[0073] Figure 4C It is a graph showing the maximum focal spot intensity at different z-coordinates according to some embodiments discussed herein, where the z-coordinate is the direction of beam propagation and is generally perpendicular to the glass sheet to be processed;

[0074] Figure 5A This is a graph illustrating different phase values ​​within an example phase mask that can be used for caustic beams according to some embodiments discussed herein;

[0075] Figure 5B The graphs show a first graph line and a second graph line according to some embodiments discussed herein. The first graph line shows the ratio of side lobe intensity to focal spot intensity as a function of aspect ratio, and the second graph line shows the ratio of focal spot width to height as a function of aspect ratio.

[0076] Figure 6 Images of example main lobes and side lobes formed by caustic beams at different aspect ratios according to some embodiments discussed herein are shown;

[0077] Figure 7A It is a graph showing the trajectory of the focal spot of a curved Bessel beam according to some embodiments discussed herein;

[0078] Figure 7B It is a graph showing the trajectory of the focal spot of a curved Bezier beam formed by the rear half of the reflected beam crossing its apex, according to some embodiments discussed herein.

[0079] Figure 8AThis is a diagram illustrating an example of a bent Bezier beam centered at the origin and using the maximum possible acceleration, according to some embodiments discussed herein;

[0080] Figure 8B It is a graph showing an example curved Bezier beam centered at the origin according to some embodiments discussed herein, where the total deflection of the example curved Bezier beam is reduced by fitting a parabola near the origin;

[0081] Figure 9A The image shows a curved Bezier beam with a contact angle of about 25 degrees according to some embodiments discussed herein, where half of the beam has been offset toward the other half to avoid creating a low-intensity area at the center of the curved Bezier beam.

[0082] Figure 9B This illustrates some embodiments for generating [something] according to the discussions herein. Figure 9A A graph showing different phase values ​​within an example phase mask of a beam;

[0083] Figure 10 It is a graph showing the maximum focused intensity as a function of the z-coordinate according to some embodiments discussed herein, in which destructive combinations of beam halves are used, constructive combinations of beam halves are used, and incoherent combinations of beam halves are used.

[0084] Figure 11A-11C These are images illustrating example polarization masks for forming curved Bessel beams according to some embodiments discussed herein;

[0085] Figure 12 This demonstrates the use of some embodiments discussed herein. Figure 11C An image of the example focal spot shape produced by the final polarization mask;

[0086] Figure 13 This is a schematic diagram illustrating an example optical system for forming a caustic beam according to some embodiments discussed herein;

[0087] Figure 14 This is a schematic diagram illustrating an example optical system for forming a curved Bessel beam according to some embodiments discussed herein;

[0088] Figure 15A This is a side sectional view showing an example section cut using a caustic beam according to some embodiments discussed herein;

[0089] Figure 15B This demonstrates a view from the edge according to some embodiments discussed herein. Figure 15A A front view of the edge of the section;

[0090] Figure 16A This is a side sectional view showing an example section cut using a curved Bezier beam according to some embodiments discussed herein;

[0091] Figure 16B This demonstrates a view from the edge according to some embodiments discussed herein. Figure 16A A front view of the edge of the section;

[0092] Figure 17 This is a block diagram illustrating an example optical system for generating and rotating a laser beam according to some embodiments discussed herein;

[0093] Figure 18A This is a schematic diagram illustrating a laser system comprising rotating optical elements in the form of a Duff prism, according to some embodiments discussed herein;

[0094] Figure 18B This is a schematic diagram illustrating a rotating optical element in the form of a k-mirror assembly according to some embodiments discussed herein;

[0095] Figure 19 It is a graph showing longitudinal profiles of Airy beams at different Y-coordinates according to some embodiments discussed herein;

[0096] Figure 20 It is a diagram showing longitudinal profiles of Airy beams at different X-coordinates according to some embodiments discussed herein;

[0097] Figure 21 It is a graph showing the intensity profiles at different locations along the propagation axis (z-axis) according to some embodiments discussed herein;

[0098] Figure 22 This is a graph showing longitudinal profiles of an Airy beam at different Y-coordinates according to some embodiments discussed herein, where the profiles have been compared with... Figure 19 Rotate the chart in the image 180 degrees;

[0099] Figure 23 This is a graph showing longitudinal profiles of an Airy beam at different X-coordinates according to some embodiments discussed herein, where the profiles have been relative to... Figure 20 Rotate the chart in the image 180 degrees;

[0100] Figure 24 This is a graph showing intensity profiles at different locations along the propagation axis (z-axis) according to some embodiments discussed herein, where the profiles have been relative to... Figure 21 Rotate the chart in the image 180 degrees;

[0101] Figure 25These are images showing examples of perforated edges formed using Airy beams according to some embodiments discussed herein;

[0102] Figure 26A This is a schematic diagram illustrating various example beam profiles of sweeping about an optical axis to form internal features in a sheet according to some embodiments discussed herein;

[0103] Figure 26B This is a schematic diagram illustrating various example beam profiles of sweeping about an optical axis to form internal features in a sheet according to some embodiments discussed herein;

[0104] Figures 27A-27B This is a schematic diagram illustrating an example process flow for forming internal features in a sheet by laser perforation and then cutting sections within the sheet according to some embodiments discussed herein;

[0105] Figure 28 This is a schematic diagram illustrating sections positioned within a sheet frame according to some embodiments discussed herein;

[0106] Figure 29 This is a schematic diagram illustrating a segment that pops out relative to the surrounding frame of the sheet according to some embodiments discussed herein;

[0107] Figure 30 This is a height map showing different locations in a sheet according to some embodiments discussed herein, where the sheet experiences popping at the edge of a segment;

[0108] Figure 31 This is a schematic diagram showing an example section separated from the remainder of the sheet by direct perforation;

[0109] Figure 32 This is a schematic diagram illustrating an example section separated from the remainder of the sheet by nonlinear perforation according to some embodiments discussed herein;

[0110] Figure 33 This is a schematic diagram illustrating an example Bessel beam optical assembly according to some embodiments discussed herein;

[0111] Figure 34 This is a graph showing an example intensity profile of a Bessel beam as a function of the focal point, according to some embodiments discussed herein;

[0112] Figure 35 These are images showing example Bessel beam cross-sections according to some embodiments discussed herein;

[0113] Figure 36This is a schematic diagram illustrating an example Bessel beam optical assembly according to some embodiments discussed herein;

[0114] Figure 37 This demonstrates the use of some embodiments discussed herein. Figure 36 The top view of a perforation formed within a sheet, similar to the Bessel beam optics shown in the image.

[0115] Figure 38 This demonstrates the use of some embodiments discussed herein. Figure 36 The image shows a front view of a cut edge formed within a sheet, similar to the Bessel beam optics shown in the image.

[0116] Figure 39A This is a side cross-sectional view showing the cut edge of an example section of sheet material according to some embodiments discussed herein, illustrating a C-shaped beveled edge formed by laser perforation using multiple angled Bezier beams;

[0117] Figure 39B This is a side cross-sectional view showing the cut edge of an example section of sheet material according to some embodiments discussed herein, illustrating a curved beveled edge formed by laser perforation using a curved laser beam;

[0118] Figure 40A Images showing example external rounded corner laser edge chamfering according to some embodiments discussed herein;

[0119] Figure 40B These are images illustrating example C-shaped beveled edges according to some embodiments discussed herein;

[0120] Figure 41A These are images showing cross-sectional intensity profiles scanned at different focal positions according to some embodiments discussed herein;

[0121] Figure 41B It is a graph showing the variation of peak grayscale intensity with focus position according to some embodiments discussed herein;

[0122] Figure 41C It is a graph showing the change of peak position as a function of focal position according to some embodiments discussed herein;

[0123] Figure 41D Images of cross-sectional intensity profiles scanned at different focal locations according to some embodiments discussed herein are shown;

[0124] Figure 41E It is a graph showing the variation of peak grayscale intensity with focus position according to some embodiments discussed herein;

[0125] Figure 41F It is a graph showing the change of peak position as a function of focal position according to some embodiments discussed herein;

[0126] Figure 42A This is a schematic diagram illustrating an example process flow for forming segments within a sheet and cutting segments according to some embodiments discussed herein;

[0127] Figure 42B It is a graph showing the edge strength of various example sheets formed using different methods according to some embodiments discussed herein;

[0128] Figure 43 Various scanning electron microscope images according to some embodiments discussed herein are shown, illustrating the increased concentration of potassium ions resulting from ion exchange around the outer surface of the sample;

[0129] Figure 44 This is a schematic top view of an internal segment formed within a sheet according to some embodiments discussed herein, which can be used in a ball-on-ring test to evaluate the force and deflection required to achieve release of the internal segment;

[0130] Figure 45 It is possible to implement some of the embodiments discussed herein. Figure 44 A schematic side view of an example setup for a ball-on-ring test on a sheet material;

[0131] Figure 46 It is a graph showing the peak load as a function of section diameter when the sheet has different thicknesses, according to some embodiments discussed herein;

[0132] Figure 47 It is a graph showing the peak load as a function of section diameter when using different chamfering methods according to some embodiments discussed herein;

[0133] Figure 48 It is a graph showing the peak load as a function of section diameter when using different chamfering methods according to some embodiments discussed herein;

[0134] Figure 49A This is a schematic diagram illustrating an example section containing a compression zone with layer depth (DOL) before the section has been pre-cut, according to some embodiments discussed herein;

[0135] Figure 49B This demonstrates the effect of brush polishing according to some embodiments discussed herein. Figure 49AThe section, and a diagram illustrating how to remove DOL during brush polishing;

[0136] Figure 49C This is a schematic diagram illustrating an example segment containing a compression zone with DOL when the segment has been pre-cut, according to some embodiments discussed herein;

[0137] Figure 49D This demonstrates the effect of brush polishing according to some embodiments discussed herein. Figure 49C The section, and a diagram showing how to keep some DOLs at the edges even after brush polishing;

[0138] Figure 50 This is a block diagram illustrating various components within an example laser system according to some embodiments discussed herein;

[0139] Figure 51 This is a flowchart illustrating example methods for modifying a sheet to form internal features, such as perforations or internal edges in the sheet, according to some embodiments discussed herein;

[0140] Figure 52 This is a flowchart illustrating an example method for forming segments of a sheet and cutting said segments according to some embodiments discussed herein, thereby manufacturing the segments cost-effectively and giving the sheet high edge strength; and

[0141] Figure 53 This is a flowchart illustrating an example method for forming a beveled edge in a sheet according to some embodiments discussed herein. Detailed Implementation

[0142] Example embodiments will now be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, of the embodiments. Additionally, unless otherwise specifically indicated, any connection or attachment may be direct or indirect. As used herein, the terms “beam” and “laser beam” are intended to be used synonymously. As used herein, “ion exchange material” may include certain ions (e.g., potassium ions, sodium ions, etc.) that diffuse into the substrate during the ion exchange process. Furthermore, some of the perforations described herein may be provided in the form of elongated lines of laser-modified material that extend throughout the entire thickness of the sheet.

[0143] Laser beveling using a non-diffractive laser beam offers numerous advantages over mechanical edge finishing. These advantages can include increased speed, accuracy, and cleanliness. However, laser beveling using a non-diffractive laser beam is generally limited by the chamfer geometry it can produce. The focal region of a non-diffractive laser beam tends to travel approximately parallel to the average direction of the local ray beam passing through that focal region; therefore, the maximum angle formed by the focal region of the laser beam relative to its optical axis (corresponding to the chamfer contact angle) is limited by the maximum angle of the rays forming the laser beam. In practice, this means that the focusing capability of the objective lens used to form the beveling beam (called numerical aperture (NA)) combined with the refraction of light at the surface of the section limits the maximum deflection that the laser beam can produce.

[0144] Figure 1 This concept is illustrated in the diagram, which is a schematic representation of an example optical assembly 100 that allows the visualization of relationships between angles in a curved light beam. Optical assembly 100 includes a lens 102 and a sheet 108, but may include other components such as a laser and other optical elements. Lens 102 is configured to focus a laser beam to produce a focused beam profile as the laser beam is directed to sheet 108. A first edge 104A and a second edge 104B of the beam profile are shown after passing through lens 102 but before passing through sheet 108. The first edge 104A defines the focal angle. And this focal angle It can be derived from the equation The definition is as follows: NA represents the numerical aperture value of the objective lens 102. The second edge 104B may have a similar focal angle. The numerical aperture value of the objective lens indicates the focusing capability of the lens 102.

[0145] When the laser beam reaches sheet 108, refraction can reduce the focal angle. Reduce to the focal angle after refraction. ,in And among them It is the refractive index of air, and This is the refractive index of sheet 108. The first edge 106A and the second edge 106B of the beam profile as the laser beam passes through sheet 108 are shown.

[0146] The curved beam has a beam profile 110, which shows the focusing region of the laser beam within the sheet 108. The focusing region can be located near the point of maximum intensity in each transverse slice of the laser beam. The curved beam profile 110 defines a contact angle θ at the entry surface 105 of the sheet 108. c1 The laser beam first enters the sheet 108 at the entry surface. Contact angle θ c1 It can be slightly lower than the focal angle after refraction. Contact angle θc1 The measurement is taken between the surface normal 105A at the entry surface 105 and the line 105B tangent to the curved beam profile 110 of the entry surface 105 adjacent to the sheet 108, where the laser beam first enters the sheet 108. Similarly, the curved beam profile 110 defines θ at the exit surface 105C of the sheet 108. c2 The laser beam exits the sheet 108 at the exit surface. Contact angle θ c2 It is measured between the surface normal 105D at the exit surface 105C and the line 105E tangent to the curved beam profile 110 immediately adjacent to the exit surface 105C. In some embodiments, the contact angle θ c1 θ c2 These contact angles θ can be equal to each other, but in other embodiments, these contact angles θ c1 θ c2 They can be different from each other. The contact angle θ mentioned in this article c It can refer to the contact angle θ c1 and / or contact angle θ c2 Contact angle θ c1 θ c2 These can all be approximately 12.5 degrees or greater, approximately 15 degrees or greater, approximately 17.5 degrees or greater, or even approximately 20 degrees or greater. Therefore, at the contact angle θ... c1 θ c2 When they are equal, the curved beam profile 110 can traverse the direction (θ) between surfaces 105 and 105C. c1 + θ c2 The changes are approximately 25 degrees or greater, approximately 30 degrees or greater, approximately 35 degrees or greater, or even approximately 40 degrees or greater.

[0147] In some embodiments, sheet 108 may comprise glass. The glass described herein, and other glasses, may be glass manufactured by Corning Incorporated, such as its Gorilla® glass or Lotus glass. TM NXT glass can be used, but other types of glass can also be used, including glass manufactured by companies other than Corning.

[0148] When the numerical aperture value of the objective lens increases, it causes and An increase in this tends to lead to an increase in the contact angle θ c1 θ c2 Increase. Objective lens numerical aperture value and maximum achievable contact angle θ c1 θ c2 The relationship between them is shown in Figure 2 In Figure 212, although the maximum achievable contact angle may be slightly lower in practice, the contact angle θ... cIt can be made by something similar to Figure 1 The optical components shown are formed, wherein the contact angle θ c Formed in a similar Figure 1 The entry surface 105, or formed at the entry surface, is... Figure 1 The exit surface is similar to the exit surface of 105C. For example... Figure 2 As shown, the maximum achievable contact angle increases with increasing objective numerical aperture value, reaching its peak at approximately 45 degrees. For some beam types, the contact angle θ increases as the objective numerical aperture value reaches higher levels, ranging from 0.8 to 1.0. c It may increase even faster. Airy laser beams, caustic laser beams, curved Bessel laser beams, and angled Bessel laser beams all exhibit contact angles θ similar to the relationship shown in Figure 212. c The relationship between the objective lens numerical aperture value and the objective lens numerical aperture value.

[0149] Despite the aforementioned limitations of using non-diffractive laser beams for laser beveling, laser beveling helps improve the impact resistance of parts. If the beveled part contacts another part or column, the contact occurs at the beveled edge of the beveled part, preventing corner cracking or chipping. In many applications, maximizing the contact angle θ may be desirable. c Furthermore, when using a non-diffractive laser beam for laser beveling, increasing the numerical aperture (NA) of the focusing objective is the primary way to achieve this. Other methods exist for laser beveling using diffractive beams (with a continuous Gaussian foci), but these methods typically require further processing, such as carbon dioxide (CO2) laser machining or etching, to release the part. These other methods also frequently result in uneven (step-like) edge profiles after release.

[0150] In the various embodiments described herein, caustic beams and certain curved Bessel beams can be used to provide high-angle cuts using diffraction-free beams. As further explained herein, these types of laser beams can be more advantageous than other laser beams, such as Airy beams and other curved Bessel beams.

[0151] like Figure 2 As shown, when using higher objective numerical aperture values ​​of approximately 0.5 or higher, Airy beams can theoretically achieve high chamfer angles. However, due to the violation of the paraxial approximation, aberrations often exist within the Airy beam. The paraxial approximation is a small-angle approximation that states sin(θ) ≈ θ, and this paraxial approximation is only considered valid for angles less than approximately 10 degrees.

[0152] To analyze the effect of the paraxial approximation on Airy beams, two different simulation techniques were used. The first, called Fresnel diffraction, relies on the paraxial approximation and propagates the beam as if the paraxial approximation were always correct. Therefore, Fresnel diffraction masks any effect of the paraxial approximation on beam propagation. The second, called Rayleigh-Sommerfeld (RS) diffraction, does not rely on the paraxial approximation. Therefore, for Airy beams, RS diffraction tends to show the effect of the paraxial approximation on beam propagation. A better understanding of the effect of the paraxial approximation on Airy beams can be achieved by comparing Airy beams formed using low and high objective numerical aperture (NA) values ​​under both Fresnel and RS propagation conditions.

[0153] Figures 3A-3D This demonstrates the use of an ideal lens with a specific objective numerical aperture value to generate an Airy beam using Fresnel or RS diffraction. Figure 3A Image 314A shows an example Airy beam propagating through Fresnel diffraction, formed using an ideal lens with a focal length of 0.4 NA. Figure 3B Image 314B shows an example Airy beam propagating through RS diffraction, formed using an ideal lens with a focal length of 0.4 NA. Figure 3C Image 314C shows an example Airy beam propagating through Fresnel diffraction, formed using an ideal lens with a focal length of 0.8 NA. Figure 3D Image 314D shows an example Airy beam propagating through RS diffraction, formed using an ideal lens with a 0.8 NA aperture.

[0154] Compare Figure 3A and 3B At a lower NA value of 0.4, only a small effect from the paraxial approximation is observed. Figure 3A The full length of the Airy beam, free from errors from the paraxial approximation, is shown. In contrast, with... Figure 3A Compared to the Airy beam in the middle, in Figure 3B In the middle, the Airy beam loses some intensity at its start and end points. For example, relative to... Figure 3A Intensity within a similar range, Figure 3B The intensity is relatively low, with the Z-coordinate ranging between -450 μm and -350 μm and between 350 μm and 450 μm. However, at the lower NA value of 0.4, the error from the paraxial approximation remains small.

[0155] However, in Figure 3C and 3D In the meantime, when the NA value increases to a higher value of 0.8, such as with... Figure 3C In comparison, Figure 3DMore severe aberrations become visible. Figure 3C The full length of the Airy beam, free from errors from the paraxial approximation, is shown. In contrast, in... Figure 3D In this case, for a 0.8 NA beam under RS ​​diffraction, severe aberrations become visible. Figure 3D In, with Figure 3C Compared to the Airy beam in the text, the Airy beam loses some intensity at both its starting and ending points. For example, compared to... Figure 3C Intensity within a similar range, Figure 3D The intensity is generally low, with the Z-coordinate ranging between -450 μm and -250 μm and between 250 μm and 450 μm. The aberrations formed when using RS diffraction and a 0.8 NA beam tend to indicate that Airy beams are not very suitable for oblique cutting with high NA values, making these Airy beams less useful for cutting applications.

[0156] Caustic beams were also studied. These caustic beams curve along a trajectory similar to Airy beams, but do not utilize the paraxial approximation in their formation. Caustic beams typically use phase approximation. The beam is formed by φ, where φ is the spherical coordinate along the direction of beam curvature, and m is a scaling factor that determines the beam length. However, this phase P1 contains a high slant angle that requires high mask resolution. Phase P1 also translates to high-angle rays behind a phase mask that requires a large-aperture lens, and the caustic beam formed using only phase P1 is more likely to be distorted by real-world objectives.

[0157] To reduce the slant of phase P1 and center the laser beam on the optical axis, a centering prism phase can be added to phase P1, resulting in a modified phase P2. This phase P2 can be calculated using the formula... We obtain, where k0 is the wavenumber of the light used to generate the beam, x is the spatial coordinate, and θ p It refers to the prism angle. By reducing the phase and the slant of the beam along the optical axis, the maximum angle of light rays in the beam can be reduced, and aberrations from real-world objectives can be reduced.

[0158] Phase P2 can also be modified to flatten the intensity profile of the caustic beam in the longitudinal direction. Airy beams generated using input beams with Gaussian intensity profiles, circular intensity profiles, or elliptical flat-top intensity profiles also exhibit intensity variations along their length. However, when generating Airy beams using square or rectangular top-hat input beams, the beams typically remain flat, with minimal intensity variation along their length. Unlike Airy beams, the focused intensity of caustic beams typically varies significantly with their length, even when formed using top-hat square or rectangular intensity profiles, usually reaching a maximum at the beam center and decreasing towards the front or rear of the beam. This low intensity near the front or rear of the caustic beam reduces the usable length of the caustic beam during cutting, thus reducing the contact angle θ that the caustic beam can achieve. c Adding a polynomial phase (as previously described) can flatten the intensity profile of the caustic beam in the longitudinal direction of the laser beam and expand its usable cutting range. The phase P2 used to form the caustic beam becomes the modified phase P3, where , where a is the scaling factor, and R is the radial coordinate across the beam aperture normalized relative to the maximum value of 1.

[0159] Figure 4A Image 416A is shown, illustrating a caustic beam propagated using RS diffraction with an NA value of 0.8. This caustic beam exhibits strong intensity throughout its entire focusing volume.

[0160] Figure 4B It demonstrates the methods used to generate Figure 4A Graph 416B shows the phase produced on the mask of the caustic beam, including two graph lines to illustrate the phase produced with and without prism phase. Graph line 417A shows the phase in radians at various X-coordinates on the mask without prism phase, and graph line 417B shows the phase in radians at various X-coordinates on the mask with prism phase. The additional prism phase can cause a significant reduction in the slope of the phase at various X-coordinates on the mask, which can reduce mask resolution requirements and decrease optical aberrations from real-world focusing lenses.

[0161] Figure 4C This is chart 416C, which shows the maximum focal spot intensity at different z-coordinates, and the z-coordinate can be roughly correlated with the focal spot intensity along the z-coordinate. Figure 1The position of beam profile 110 corresponds to the position of z = 0, which corresponds to the center of the sheet. Figure line 417C shows the caustic beam in watts per square centimeter (W / cm²) without additional polynomial phase at various Z-coordinates. 2 The maximum focal spot intensity is expressed in watts per square centimeter (W / cm²), and graph line 417D shows the caustic beam in watts per square centimeter (W / cm²) under various conditions with additional polynomial phase at different Z-coordinates. 2 The maximum focal spot intensity is expressed in units of ). Compared to graph line 417C without using an additional polynomial phase, graph line 417D with an additional polynomial phase has a flattened curve, allowing for an extended cutting range of the laser beam. Without using an additional polynomial phase, the contact angle θ c (In some embodiments, it may correspond to an angle of approximately 30 degrees when the beam intensity reaches approximately 80% of its maximum intensity) and the contact angle θ of the caustic beam in the case of an additional polynomial phase. c The angle is approximately 35 degrees. The prism phase was also evaluated in simulations using an ideal focusing lens and sufficient resolution, but the prism phase had no significant effect on graph lines 417C and 417D.

[0162] When cutting glass using Airy and caustic beams, sidelobe absorption is often a serious problem due to the relatively low intensity contrast between the focused and sidelobe regions of these beams. Absorption in the sidelobes can reduce the available power of the main lobe for deep cuts within the sheet. Additionally, sidelobe absorption can cause cracking perpendicular to the cutting direction, which can reduce the strength of the cut part. Sidelobe absorption can also damage and roughen the surface of the sheet, thereby lowering the laser damage threshold in the roughened areas. Due to the focal spot shape of Airy and caustic beams, the sidelobes of each laser beam (or burst) may overlap with those of the previous emission, which can cause severe damage to the sheet in the overlapping areas.

[0163] The shot-to-shot overlap and intensity contrast between the side lobes and the main lobe can be improved by varying the spatial extent of the Airy beam. These issues can also be addressed by using an elliptical or rectangular top-hat shaped intensity profile instead of a circular or square one. However, using an elliptical or rectangular intensity profile may result in an elliptical focal spot shape, which could force cracks to grow in a direction parallel to the cutting process.

[0164] Figures 5A-5B Figures 6 and 7 demonstrate the effect of using a rectangular input beam to produce a caustic beam. Figure 5AThis is Graph 518A, which illustrates different phase values ​​within an example phase mask that can be used for caustic beams. Graph 518A shows the phase at various X- and Y-coordinates of the phase mask, and the color bars on the right of Graph 518A display the phase values ​​corresponding to the colors in Graph 518A, where the phase values ​​are expressed in radians. Caustic beam generation systems typically consist of a circular Gaussian beam centered on the phase mask. However, here, the caustic beam generation system comprises a beam with a cross-section indicated by a rectangular shape 519. Changing the aspect ratio of this rectangular shape 519 alters the focal spot of the caustic beam without affecting its diffraction-free properties.

[0165] Figure 5B This is chart 518B with an aspect ratio on the x-axis. Chart line 521A corresponds to the y-axis shown on the upper left of chart 518B, where chart line 521A displays the intensity ratio on the y-axis. This intensity ratio is the sidelobe intensity (Max( )) and focal spot intensity (Max(I) ML The intensity ratio is approximately 0.46 when the aspect ratio is approximately 0.15. However, the intensity ratio then decreases at a high rate, dropping to approximately 0.25 when the aspect ratio increases to approximately 0.16. Therefore, the maximum brightness of the sidelobes is approximately 25% of the maximum brightness of the main lobe. When the aspect ratio increases to approximately 0.25, the intensity ratio increases significantly to 0.6. As the aspect ratio increases from 0.25 to approximately 1.0, the intensity ratio remains at approximately 0.60.

[0166] Figure 5B The graph line 521B corresponds to the y-axis shown on the upper right side of graph 518B, where graph line 521B illustrates the focal spot width to height ratio. When the aspect ratio is less than 0.2, the focal spot width to height ratio is typically at a high level, above about 0.8. As the aspect ratio increases from 0.1 to 0.2, the focal spot width to height ratio decreases significantly from about 1.2 to about 0.75. However, as the aspect ratio increases from 0.2 to 1.0, the focal spot width to height ratio decreases at a significantly lower rate, with the ratio only slightly less than 0.75 at an aspect ratio of 1.0. Reducing the input beam (moving it to the left in graph 518B) increases the focal spot width to height ratio, making the focal spot wider than its height, thereby forcing crack formation parallel to the cutting plane.

[0167] In addition, Figure 6Images of example main lobes and side lobes formed by caustic beams with different aspect ratios are shown. Image 620A shows the caustic beam focal spot with an aspect ratio of 1, image 620B shows the caustic beam focal spot with an aspect ratio of 0.2, image 620C shows the caustic beam focal spot with an aspect ratio of 0.16, and image 620D shows the caustic beam focal spot with an aspect ratio of 0.1.

[0168] Image 620A shows the main lobe 621A and side lobe 623A. Image 620B shows the main lobe 621B and side lobe 623B. Image 620C shows the main lobe 621C and side lobe 623C. Finally, image 620D shows the main lobe 621D and side lobe 623D. As used herein, the side lobes can be positioned laterally or directly below the main lobe. The main lobes 621A-621D each have greater intensity or brightness than the other side lobes 623A-623D.

[0169] Figure 6 Images 620C and 620D show caustic beam focal spots with low sidelobe intensity and elliptical shapes. As the input beam becomes more rectangular, the horizontal extent of the sidelobes decreases, with the sidelobes positioned in a narrower location below the main lobe. For example, in image 620A, sidelobe 623A extends a considerable distance horizontally relative to the main lobe 621A. When the aspect ratio decreases, the sidelobes are positioned in a narrower location below the main lobe. For example, in image 620D using the minimum aspect ratio, sidelobe 623D is almost entirely positioned below the main lobe 621D.

[0170] Combining an elliptical focal spot shape with bursts of emitted laser pulses can reduce beam intensity and further decrease sidelobe absorption while maintaining sufficient total energy in the beam for laser cutting. In some embodiments, bursts may each comprise five or more pulses, with time delays between pulses within a burst. In some embodiments, the time delay between pulses within a burst can be approximately 12 nanoseconds. In contrast, reducing beam energy may reduce sidelobe absorption, but this reduction may result in insufficient total energy in the beam for laser cutting. Additionally, laser emission with multiple pulses per burst can produce larger cracks, enabling cutting at greater intervals without overlapping emission sidelobes.

[0171] In addition to the other beams discussed in this paper, bent Bessel beams can be used to obtain beveled edges with contact angles of approximately 15 degrees or greater, or even approximately 20 degrees or greater. A bent Bessel beam is a non-diffractive beam with a Bessel-like focal point, which follows a shaped trajectory as it propagates. Bent Bessel beams can cut glass with beveled edges in a manner similar to Airy and caustic beams. Bent Bessel beams have a maximum angular constraint related to the focal lens's NA, similar to that of Airy and caustic beams. However, bent Bessel beams have an additional constraint on the maximum lateral acceleration at the focal spot location, which can significantly reduce the maximum contact angle θ that a bent Bessel beam can achieve. c This constraint is equal to:

[0172]

[0173] in It is a constant related to the focusing power of the beam, and z is the distance from the origin of the beam. Describe the path of the beam, and Describes the second derivative along the beam path. This remains unchanged in this case. This equation can be solved. Integrate twice to find the one with the maximum acceleration. (And thus obtain the maximum curvature and maximum contact angle). This yields the following equation:

[0174]

[0175] Where b is a constant used to offset the vertex of the beam to its center point (this constant is chosen to satisfy the equation f'(z) = 0, where z = L / 2, and where L is the target length of the beam), and c is a small constant chosen to prevent infinite acceleration at the origin. These constraints limit the contact angle achievable by a curved Bessel beam. Ideally, it is desirable to manipulate the beam to achieve an angle as close as possible to the angle of a caustic beam. This can be achieved by a curved Bessel beam following the trajectory given in equation (2). However, as in Figure 7A As seen in the image, this beam does not exhibit reflection symmetry across its apex.

[0176] Figure 7AA graph 722A is shown illustrating the trajectory of the focal spot of the curved Bessel beam generated using equation (2) above. In graph 722A, the x-axis represents the z-coordinate, which is the position along the optical axis, expressed as a percentage ranging from 0% to 100%. Additionally, in graph 722A, the y-axis represents the x-coordinate, which is the position along the acceleration axis, expressed as a percentage ranging from 0% to 100%. The focal line 725 extends downwards at approximately 50% of the Z-coordinate in the middle of graph 722A. The first half 727A of the graph line is shown to the left of the focal line 725, while the second half 727B is shown to the right of the focal line 725. The lack of reflection symmetry across the focal line 725 may cause asymmetrical chamfering, where the first half 727A differs significantly from the second half 727B.

[0177] Figure 7B Graph 722B illustrates the trajectory of the focal spot of a curved Bessel beam, formed by reflecting the second half 727D of the beam across the beam's apex at focal line 725 using the aforementioned Equation 2. In Graph 722B, the x-axis represents the z-coordinate, the position along the optical axis, expressed as a percentage ranging from 0% to 100%. Similarly, in Graph 722B, the y-axis represents the x-coordinate, the position along the acceleration axis, expressed as a percentage ranging from 0% to 100%. Figure 7A In Figure 722A, the first half 727C of the graph line is shown to the left of the focal line 725, while the second half 727D of the graph line is shown to the right of the focal line 725. The first half 727C is symmetrical to the second half 727D by reflecting the beam across the focal line 725. Although Figure 722B is symmetrical about the focal line 725, this reduces the overall curvature of the beam by making the constraint from Equation (1) significantly heavier. In fact, the maximum contact angle of the bent Bessel beam produced using this method and a 0.8 NA lens is about 12 degrees, and this is far below the contact angle achievable by a caustic beam.

[0178] Another method to form a symmetrical beam is to form only half of the beam behind the focal line and then reflect the beam across the focal line at the origin. Such a beam can be formed by using equation (2) and setting b = 0. In this case, the beam vertex is located at z = 0, thus allowing the beam to be formed using accelerations up to the maximum limits given in equation (1).

[0179] Figure 8AFigure 824A illustrates the trajectory of such a curved Bezier beam, centered at the origin and using the maximum possible acceleration. The curved Bezier beam formed with b = 0 exhibits extremely high acceleration near the origin, determined by the value chosen for c, resulting in a less than ideal shape. For the curved Bezier beam shown in Figure 824A, the value of c is set to 0.1. However, the value of c can have a variety of other values.

[0180] The shape can be improved by starting the beam's trajectory on a parabolic path near the origin and transitioning to the trajectory given by equation (2) at z = p. The modified trajectory is given in the following equation:

[0181]

[0182] Figure 8B The beam produced using Equation 3 is shown, where Figure 8B Figure 824B in the figure shows an example curved Bezier beam centered at the origin, where the total deflection is reduced by fitting a parabola near the origin. Figure 8B The beam of light in the middle is relative to Figure 8A The beam has an improved shape. The maximum angle that the beam can reach can be tuned by selecting the variable p, and said maximum angle can be selected to suit the experimental system.

[0183] To reflect the beam across a line at the origin, the phase mask of the beam can be changed to a binary mask using the following equation:

[0184]

[0185] in It is the phase of the curved Bessel beam confined to the range [0, 2π), wherein the range includes 0, and the range extends to at most but not including 2π, and wherein This is the phase of the binary mask. In a binary mask of height π, the + / -1st order diffractions have equal power and are directed such that the -1st order is reflected across the line at the origin relative to the +1st order, thus... Figure 8A and 8B The trajectory shown forms a perfectly symmetrical oblique-cut beam. The first half of the curved Bessel beam can be formed experimentally downstream, near the conjugate plane of the 4f system, and the other half can be formed upstream, also near the conjugate plane of the 4f system. A curved Bessel beam of sufficient length to cut glass can be generated by matching the input beam size to the phase mask used. However, due to the significant difference between the intensity of the Gaussian beam (which is flat near the center) and the intensity required to maintain a constant intensity through the beam's focus, a low-intensity region may exist near the center of the beam.

[0186] In practice, low-intensity zones often leave unperforated sections near the center of sheets (e.g., glass sheets), significantly reducing the effectiveness of the cutting process. To prevent the formation of low-intensity zones, one of the two halves of a bent Bezier beam can be modified to change its focusing position, such that for both the modified and unmodified beam halves, point z... f = 0 appears at different absolute values ​​of z. Therefore, the modified and unmodified beam halves can be effectively moved closer to each other. Changing the focusing position of the beam can be achieved by emitting a portion of the beam through a thick glass plate. By emitting the beam through a thick glass plate, the focus of the beam may be shifted. In some embodiments, this can shift the focus of the beam by approximately half the thickness of the plate (shift factor n). glass - n air However, the focusing position of the beam can be adjusted in other ways.

[0187] Figure 9A Figure 926A illustrates a curved Bessel beam with a contact angle of approximately 25 degrees. Similar to the example described above, the curved Bessel beam is generated by forming two separate beams that intersect at a z-coordinate of approximately 500 micrometers. To form the curved Bessel beam, a piece of glass is placed in the path of one of the beams to effectively bring the two beams closer together. By bringing these beams closer together, a low-intensity region at the center of the curved Bessel beam (e.g., around the z-coordinate of approximately 500 micrometers) can be avoided. Otherwise, a low-intensity region could exist near the center of the beam due to the significant difference between the intensity of the Gaussian beam (which is flat near the center) and the intensity required to maintain a constant intensity through the focal point of the beam.

[0188] Figure 9B It demonstrates what can be used to generate Figure 9A Figure 926B shows different phase values ​​within an example phase mask for a curved Bessel beam. Figure 9B In the phase mask, all phase values ​​within the phase mask are 0 or 0. Two additional modifications were made to the curved Bessel beam to improve beam quality and cutting performance. One modification produced an elliptical focal spot shape to force the crack direction parallel to the cutting direction. Another modification eliminated interference at the intersection of the two beam halves; this was achieved by rotating the polarization of the beam halves so that their polarizations were orthogonal to each other (in some embodiments, this modification can be achieved simultaneously using a split quarter-wave plate and crack propagation control (CPC)).

[0189] A method called crack propagation control (CPC) is commonly used to generate elliptical focal spots in Bessel beams. In the CPC method, the polarization of one half of the Bessel beam is rotated by 90 degrees. This causes the two halves of the beam to combine incoherently, resulting in the formation of an elliptical focal spot. Another method to achieve a similar focal spot shape is to block a portion of the beam, but this method reduces the system's power throughput.

[0190] If one half of a Bessel beam is bent to connect the two sides at the center, the beams from each side will interfere with each other. The resulting interference depends on the relative phase between the two beams, and this relative phase is random when a thick glass plate is used to delay one beam. The relative phase depends on the thickness of the plate relative to an integer number of laser wavelengths. Rotating the polarization of one half of the beam to be orthogonal to the other half will cause the two beams to combine incoherently and prevent interference.

[0191] Figure 10 Graph 1028 shows the maximum focused intensity in the beam relative to the z-coordinate in the beam, where the beam is combined in the form of destructive combinations, constructive combinations, and incoherent combinations of the beam halves. As previously mentioned, the z-coordinate corresponds to the position along the optical axis. Graph line 1028A shows data for destructive combinations, graph line 1028B shows data for constructive combinations, and graph line 1028C shows data for incoherent combinations. The incoherently combined curved Bezier beam, represented by graph line 1028C, has a more consistent intensity profile along its entire length, which produces a higher quality cut and prevents destructive conditions. Figure 10 In the middle, half of the beam was offset by 150 micrometers to form a combination.

[0192] Different types of polarization masks can be used to form curved Bessel beams with desired characteristics. Figure 11A-11C This is an image showing both an example polarization mask and the curved Bezier beam formed by the polarization mask in a background image. These polarization masks have different combinations of polarization rotations, allowing the formation of curved Bezier beams with different properties. For example, different parts of the polarization mask can undergo polarization rotation to control the focal spot shape, and incoherent combinations of adjacent beams can be achieved using a single mask.

[0193] In image 1130A, an intensity profile 1134A of the curved Bessel beam in the Fourier plane is shown in the background image. A circle 1132A representing the aperture of the focusing lens is also shown. Image 1130A also shows a polarization mask comprising a first half 1136A and a second half 1136B. The first half 1136A is positioned above the second half 1136B. In the polarization mask in image 1130A, the polarization of the first half 1136A is rotated by approximately 90 degrees, while the polarization of the second half 1136B is not rotated. The combination of the first half 1136A and the second half 1136B in the polarization mask ensures an incoherent combination of the beam halves of the curved Bessel beam, but this combination cannot effectively form a focal spot with an elliptical shape.

[0194] In image 1130B, an intensity profile 1134B of a curved Bessel beam in the Fourier plane is shown against the background image. A circle 1132B representing the aperture of the focusing lens is also shown. Image 1130B also shows a polarization mask comprising a first half 1136C and a second half 1136D. Figure 11B In the polarization mask, the first half 1136C is positioned to the left of the second half 1136D. In the polarization mask in image 1130B, the polarization of the first half 1136C is rotated by approximately 90 degrees, while the polarization of the second half 1136D is not rotated. The combination of the first half 1136C and the second half 1136D in the polarization mask can help form an elliptical focal spot, but this combination does not effectively ensure the incoherent combination of the beam halves of the curved Bessel beam.

[0195] Although Figure 11A and 11B Each of these polarization masks is not very effective in various ways, but Figure 11C The polarization mask shown in image 1130C effectively ensures the incoherent combination of the beam halves while forming a focal spot with a strongly elliptical shape. In image 1130C, an intensity profile 1134C of the bent Bessel beam in the Fourier plane is shown in the background image. A circle 1132C representing the focusing lens aperture is also shown. Image 1130C also shows a polarization mask comprising a first quarter 1136E, a second quarter 1136F, a third quarter 1136G, and a fourth quarter 1136H. In the polarization mask in image 1130C, the polarizations of the first quarter 1136E and the fourth quarter 1136H are rotated by approximately 90 degrees, while the polarizations of the second quarter 1136F and the third quarter 1136G are not rotated. The combination of quarters 1136E-1136H in the polarization mask helps to form an elliptical focal spot while ensuring the incoherent combination of the beam halves of the bent Bessel beam.

[0196] A segmented quarter-wave plate can be produced by cutting it into four sections and flipping the opposite corners to create a pattern similar to... Figure 11C A prototype mask similar to the one shown in Image 1130C. When a split quarter-wave plate is combined with another quarter-wave plate such that the input polarization of the split quarter-wave plate is circular, this can produce a similar effect to... Figure 11C The polarization state is similar to that shown in the diagram. The resulting curved Bessel beam can have a polarization state similar to that shown in the diagram. Figure 12 The shape of the focal spot shown in image 1238 allows for strong control over the crack direction during the cutting process. Figure 12 The shape of the foci has a strong ellipticity.

[0197] In addition, Figure 9B The binary phase mask in Figure 926B can be fabricated as a diffractive optics device using orthogonal polarization feature elements in the 0 and π phase regions. For example, if orthogonal linear polarization regions are used, an input beam with circular polarization (e.g., through an upstream quarter-wave plate) can be simultaneously separated into a principal beam component and a reflected beam component. Binary phase masks can also be formed using metasurface optics designed with polarization-sensitive features. Metasurfaces can also be generated to represent non-binary designs that use polarization-sensitive features for sampling to distribute energy uniformly to each principal and reflected beam.

[0198] This paper describes both caustic beams suitable for high-angle skewing and curved Bessel beams. The phase mask used for caustic beams can be similar to... Figure 5A The phase mask shown in the figure, and the phase mask used for bending Bessel beams can be similar to Figure 9B The phase mask shown is an example. Phase masks for generating caustic beams and bent Bessel beams can be generated using a spatial light modulator (SLM). An SLM is a device that applies a phase between 0 and 2π (in 256 steps) to the incident laser beam reflected by the SLM at each individual pixel. Phase masks can have a resolution of 1152 pixels by 1920 pixels, with a pixel pitch of approximately 8 micrometers, but other resolutions and pixel pitches can also be used for phase masks.

[0199] Figure 13This is a schematic diagram illustrating an example caustic beam optics system 1340 for caustic beam formation. In the case of a caustic beam, beam 1342 is initially a Gaussian beam before reaching elliptic forming element 1344. Elliptic forming element 1344 can reshape the beam 1342 into an elliptical Gaussian beam before it strikes SLM 1346, and this helps maintain the power efficiency of the beam before it is reflected by SLM 1346. A phase mask may be shown on SLM 1346. Elliptic forming element 1344 may be provided in the form of one or more lenses (e.g., cylindrical lenses) or pairs of deformable prisms, but it may also be provided in other forms. However, elliptic forming element 1344 may be replaced with other optical elements that reshape the input beam intensity into other shapes (e.g., rectangles, squares, circles, etc.). The beam 1342 is then re-imaged through lenses 1348 and 1350, which are provided in a 4f optical configuration. The beam 1342 is then focused through lens 1352, which has a high field of view (NA) (e.g., NA is about 0.6 or greater), thereby generating a focused beam 1342A. The focused beam 1342A is directed to sheet 1354 to generate a laser beam with a profile 1356 at sheet 1354.

[0200] Figure 14 This is a schematic diagram illustrating an example bent Bessel beam optical system 1440 for bent Bessel beam formation. For a bent Bessel beam, beam 1442 is initially provided as a simple Gaussian beam. Beam 1442 is reflected by an SLM 1446, on which a phase mask can be displayed. Beam 1442 is then re-imaged through lenses 1448 and 1450, which are provided in a 4f optical configuration. The bent Bessel beam optical system 1440 can be configured without similar... Figure 13 Lens 1352 is any focusing lens. Because no focusing lens similar to lens 1352 is provided in the curved Bessel beam optical system 1440, lens 1450 can have a high NA (e.g., NA of about 0.6 or greater). The magnification of lenses 1448 and 1450 is typically close to 1:1, but the magnification of the curved Bessel beam optical system 1440 can be as low as 1:70, so beam 1442 is reduced by up to 70 times. Lens 1450 produces a focused beam 1442A, which is directed toward sheet 1454. Optical retardation element 1458 is positioned between lens 1450 and sheet 1454, wherein optical retardation element 1458 is provided in the form of a block comprising glass or another material. As described herein (e.g., refer to...). Figure 9AThe optical delay element 1458 can be used to spatially offset one half of the focused beam 1442A relative to the other half along the length of the focused beam 1442A. The focused beam 1442A is then guided to the sheet 1454 to produce a profile 1456 at the sheet 1454. Although the illustrated curved Bessel beam optical system 1440 does not include a split quarter-wave plate, a split quarter-wave plate can be placed between lenses 1448 and 1450 in use.

[0201] High-angle slanted beams typically require objective numerical aperture values ​​greater than approximately 0.65 and longer working distances for ease of fabrication. With objective numerical aperture values ​​greater than approximately 0.65, aberrations can naturally occur, and sensitivity to angular inputs may increase. Light in high-angle slanted beams is incident at a relatively large angle, and most focusing objectives are designed for plane wave inputs. As a result, some aberrations may occur when the slanted beam passes through a real-world optical system. Additional aberrations arising from refraction into a sheet (e.g., a glass plate) become more pronounced with higher-angle beams.

[0202] Several methods exist for correcting these aberrations. These methods include backpropagation, neural networks with forward propagation, phase retrieval algorithms, and in-situ correction. For backpropagation, a “perfect” beam (typically using an ideal lens) is generated in a simulation and propagated into its focal region. The beam is then reversed and propagated backward through a real-world optical system. After propagating through all optical elements back to the SLM's position, the beam's phase is used to replace the original phase mask of the beam. This backpropagation method can also be used to fix aberrations entering the glass by generating a perfect beam inside the glass and refracting it through the glass-air interface during backpropagation. This backpropagation method is very effective but requires a precise understanding of the optical system and its components.

[0203] Aberration correction can also be achieved using neural networks with forward propagation. In this method, a perfect beam can be generated and then perturbed with various aberrations. These aberrations are typically defined by the Zernike coefficient. A computer and / or neural network can then be trained to identify the aberration phases that cause certain defects in the final curved beam. A camera can be used to image the beam in the experimental system, and the computer and / or neural network can be used to determine the phase function of the aberrations in the experimental beam. A reverse phase can be added to the original phase mask to fix the beam. Aberrations entering the glass can be recorded by placing the glass sample in the focal region of the beam during the imaging step. Care should be taken to prevent additional refraction from the glass slide through a refractive index-matching fluid when performing this method.

[0204] Phase retrieval algorithms can also be used to correct aberrations. These include algorithms such as the Gerchberg-Saxton algorithm or the adjoint state method. A phase retrieval algorithm derives the phase of a beam from an image of the beam in the focal plane. An experimental image of the beam can be fed into the phase retrieval algorithm to obtain the phase of the experimental beam. This phase of the experimental beam can then be compared with the desired phase, and a phase mask can be designed to correct aberrations in the experimental system. Aberrations entering the glass can be recorded by placing the glass sample in the focal region of the beam during the imaging step. When performing this method, care should be taken to prevent additional refraction from the glass slide through a refractive index-matching fluid.

[0205] Other in-situ correction methods can also be used to correct aberrations. These methods typically involve using wavefront sensors, interferometers, or iterative beam correction. In the case of wavefront sensors or interferometers, information about the beam can be used to determine its phase, which is then compared to an ideal phase for correction. Iterative schemes add different phases to a phase mask on the SLM and use a camera to record the resulting beam, moving towards a higher quality beam. Machine learning algorithms can be used to guide the selection of the correction phase and increase the speed of the process.

[0206] Experiments were conducted to generate caustic beams and bent Bessel beams. For caustic beams, a deformable prism was used to reproduce the results. Figure 13 The experimental system described herein is designed to generate an elliptical beam. This system comprises a 0.83 NA aspherical focusing lens (e.g., an EO 22-758 lens) and a pulsed ultrafast laser. The pulsed ultrafast laser has a pulse width of approximately 8 picoseconds, a pulse energy of approximately 1.2 millijoules, a burst number of 8, a repetition rate of approximately 10 kHz, a wavelength of approximately 1030 nm, and a Gaussian spatial profile diameter of approximately 16 mm. However, different lasers can be used in other embodiments, and the lasers can operate with different characteristics. Due to the limited availability of commercially available lenses with suitable working distances and NAs, the purchased lens was designed for a wavelength of 587.6 nm, which resulted in significant aberrations being imposed on the beam as it propagates through the lens. The previously mentioned backpropagation method is used to correct these aberrations. Additionally, in-situ correction is used to correct residual aberrations due to form deviations within the lens.

[0207] After laser processing using this experimental system, mechanical force is manually applied to cause the sheet to break along the perforation line. Figures 15A-15B The resulting cut sections are shown in the figure. Figure 15AIt shows a side sectional view of example section 1560 cut using caustic beam cutting, and Figure 15B It is a demonstration Figure 15A A front view of the edge of segment 1560 is provided to show the quality of the cut edge. The thickness of segment 1560 between the first surface 1563A and the second surface 1563B is approximately 700 micrometers. To form the beveled edge in segment 1560, segment 1560 is positioned on a mechanical stage and then translated under a laser-generated beam. The beam is provided in bursts, each burst consisting of eight pulses. Each burst produces a single, curved perforation through the glass sheet. The movement speed of the mechanical stage and the laser emission rate are controlled such that a spacing of approximately 10 micrometers exists between adjacent perforations.

[0208] The resulting beveled edge includes a first portion 1562A, a second portion 1562B, and a vertex 1562 located between the first portion 1562A and the second portion 1562B. Vertex 1562 is typically located between the first portion 1562A and the second portion 1562B. Figures 15A-15B The points of intersection in the shown segment 1560. The first portion 1562A of the beveled edge intersects the first surface 1563A at corner 1565A, and the second portion 1562B of the beveled edge intersects the second surface 1563B at corner 1565B. The second portion 1562B defines a contact angle θ1 relative to a direction perpendicular to the second surface 1563B, wherein this angle θ1 is measured using a line approximately tangent to the second portion 1562B at corner 1565B. In the shown embodiment, this contact angle θ1 is approximately 20 degrees. Therefore, the angle defined between the plane formed by the second surface 1563B and the line approximately tangent to the second portion 1562B at corner 1565B is approximately 110 degrees. The angle defined at the first surface 1563A is slightly lower than the angle defined at the second part 1562B, and this is due to aberrations in the lens that are introduced by manufacturing errors in the lens and are not fully corrected before processing.

[0209] Experiments were also conducted to generate bent Bessel beams. The experimental system included a 0.6 NA aspherical focusing lens and a pulsed ultrafast laser. The pulsed ultrafast laser had a pulse width of approximately 8 picoseconds, a pulse energy of approximately 1.2 millijoules, a burst number of 8, a repetition rate of approximately 10 kHz, a wavelength of approximately 1030 nanometers, and a Gaussian spatial profile diameter of approximately 8 millimeters. However, different lasers can be used in other embodiments, and the lasers can operate with different characteristics.

[0210] The sheet is placed on a mechanical stage and perforated along a line using a bent Bezier beam. The thickness of the sheet between the first surface 1663A and the second surface 1663B is approximately 700 micrometers. The movement speed of the mechanical stage and the laser emission rate are controlled to maintain a spacing of approximately 10 micrometers between adjacent perforations.

[0211] After laser processing using this experimental system, mechanical force is used to separate sections of the sheet. Figures 16A-16B The image shows the separated segments. Figure 16A This is a side cross-sectional view showing an example segment 1664 cut using a curved Bezier beam. Segment 1664 has a first surface 1663A and a second surface 1663B opposite to the first surface 1663A. Segment 1664 also has a beveled edge comprising a first portion 1666A, a second portion 1666B, and a vertex 1666 positioned between the first portion 1666A and the second portion 1666B. The first portion 1666A of the beveled edge intersects the first surface 1663A at a corner 1665A, and the second portion 1666B of the beveled edge intersects the second surface 1663B at a corner 1665B.

[0212] The second portion 1666B extends at an angle θ2 relative to line 1669A perpendicular to the second surface 1663B. This angle θ2 is measured relative to line 1669B, which is tangent to the second portion 1666B at corner 1665B. Angle θ2 is approximately 15 degrees. Due to the lower NA objective used to form the curved Bezier beam, this angle θ2 is lower than the contact angle formed using a caustic beam. However, even when using a curved Bezier beam, using a higher NA objective can allow for a higher contact angle of approximately 20 degrees or more.

[0213] Figure 16B It is a demonstration Figure 16A A front view of the edge of section 1664. Figure 16B Each visible vertical line is a perforation produced by a single laser emission from the laser. The damage morphology resembles a perforation cut using a direct Bezier beam. An unperforated stripe 1667 exists near the center of the beveled edge. Since a split quarter-wave plate was not used when forming the edge, this unperforated stripe 1667 is likely formed due to beam interference.

[0214] Figure 17This is a block diagram illustrating an example optical system 1768 for generating and rotating a laser beam. The optical system 1768 can be configured to subject a sheet to laser processing such that the laser beam has a specific spatiotemporal shape. The optical system 1768 includes a laser 1770 configured to assist in generating the laser beam. In some embodiments, this laser beam can be an Airy beam, a caustic beam, or a Bessel beam, but in other embodiments, other laser beams can be formed. Other components (e.g., elements 1772, 1774, 1776, 1778) can also help shape or otherwise modify the laser beam. In other embodiments, the laser 1770 can be configured to generate the laser beam in the form of a series of pulse bursts, each of which contains multiple pulses, and a time delay is provided between each of the pulses. In some embodiments, the time delay can be at least about 12 nanoseconds, but different time delay values ​​can be used in other embodiments. The laser 1770 can operate with characteristics similar to those used in other lasers described herein.

[0215] In some embodiments, the optical system 1768 may include one or more preparatory optical elements 1772. The preparatory optical elements 1772 may be configured to guide a laser beam from the laser 1770 to the space shaping system 1774, and the preparatory optical elements 1772 may achieve this in various ways, such as by reflection, refraction, or other methods.

[0216] The space shaping system 1774 can be configured to receive a laser beam to adjust the beam profile of the laser beam. For example, the space shaping system 1774 can be configured to apply variations to the spatial and / or temporal profile of the laser beam. The space shaping system 1774 can be provided in various forms. For example, in some embodiments, the space shaping system can be a passive shaping system. When the space shaping system is a passive shaping system, it can include at least one of the following: a fixed diffractive optical element, a phase plate, or another optical system configured to apply a rotationally asymmetric amplitude and / or phase profile to the laser beam. In other embodiments, the space shaping system can be an active shaping system. When the space shaping system is an active shaping system, it can include a spatial light modulator, such as a liquid crystal element or a digital micromirror device. However, in other embodiments, the space shaping system can have other forms.

[0217] In some embodiments, a space shaping system 1774 may be used to form a first beam profile of the laser beam received at the rotating optical element. In some embodiments, one or more additional optical elements 1776 and one or more polarization control elements 1778 may also be included to aid in forming the first beam profile of the laser beam received at the rotatable optical element 1780. The polarization control element 1778 may be configured to adjust the polarization of the laser beam before it is received at the rotatable optical element 1780, and the additional optical elements 1776 may be configured to apply further changes to the laser beam before it is received at the rotatable optical element 1780. The polarization control element 1778 may include one or more of the following: a polarizer (e.g., a linear polarizer or a circular polarizer), a waveplate (e.g., a quarter-wave plate, a split quarter-wave plate, a half-wave plate, etc.), a birefringent material, and / or other elements.

[0218] A laser beam can be received at a rotatable optical element 1780, and the rotatable optical element 1780 can be rotated to rotate the laser profile about an axis. Examples of rotatable optical elements are described in more detail herein. In some embodiments, the rotatable optical element can be similar to... Figure 18A The rotatable optical element 1892. When a laser beam is actively guided to the rotatable optical element, the rotatable optical element can rotate. By doing so, internal features can be formed in the sheet. When the rotatable optical element rotates, the beam profile of the laser emanating from the rotatable optical element can rotate at a rate faster than the rotatable optical element itself (e.g., twice as fast).

[0219] One or more final optical elements 1782 are also provided, and these elements 1782 can be configured to adjust the laser beam after it exits through the rotatable optical element 1780 but before it reaches the sheet 1784. In some embodiments, the final optical element 1782 can be configured to focus the laser beam.

[0220] The final optical element 1782 may include a focusing element and possibly other optical elements that can maintain or alter the relative spatial and temporal characteristics of the beam. These final optical elements 1782 produce a spatiotemporal beam profile in the sheet 1784, which is well controlled to obtain desired results, such as cut edges.

[0221] In some embodiments, sheet 1784 may comprise glass. A spacetime beam ultimately reaches sheet 1784. Once in sheet 1784, the spacetime beam can modify the material within sheet 1784 to form one of the modifications described herein. The modification can be a permanent material modification, and the modification can have a three-dimensional form controlled by the forming element. The modification may optionally include perforation (e.g., cracking), refractive index modification, voids, densification, or changes in chemical bonding within the material. The spacetime beam can also produce transient modifications, such as three-dimensional melting or color center generation, as determined by the forming beam. Temporary or permanent modifications can be used as is, or these modifications can be utilized in additional processes to form the final part. For example, additional processes may include laser-induced cracking to provide a path for separation via deflection or other laser processes. Additionally or alternatively, additional processes may include etch-based feature release (e.g., acid etching, corrosive etching, etc.), application of transient chemical features to obtain increased subsurface light absorption, or formation of vias (e.g., through-glass vias). Other processes may also be used.

[0222] Sheet 1784 can be positioned on motion control unit 1786, wherein motion control unit 1786 is configured to move sheet 1784 relative to other components of optical system 1768, such that modifications can be formed at different locations within sheet 1784. For example, a modification (e.g., perforation) can be formed at one location within sheet 1784, and motion control unit 1786 can be configured to adjust the position of sheet 1784 before forming another modification at another location within sheet 1784. For example, motion control unit 1786 can be configured to reposition sheet 1784 after one or more laser bursts or after one or more pulses within a burst. Motion control unit 1786 may include linear actuators, rotary actuators, motors (e.g., DC motors, AC motors, stepper motors, servo motors, etc.), programmable logic controllers, sensors, and / or other components.

[0223] Optionally, in some embodiments, elements configured to aid in temporal shaping may be provided. These elements may be positioned at a point in the system path. In some embodiments, temporal shaping may be achieved using a laser with a laser pulse “burst mode.” Alternatively or additionally, an active 4-f temporal shaping system may be used, wherein the active 4-f temporal shaping system acts as an optical element. These temporal shaping optics allow for time control coupled to specific beam profiles to further tune the laser-material interaction.

[0224] Although the components in the optical system 1768 are Figure 17The elements are shown in a specific order and arrangement, but in other embodiments, the order and arrangement of the elements may be changed.

[0225] Rotatable optical elements can be provided in various forms, and Figure 18A This is a schematic diagram illustrating a laser system 1888 having a rotatable optical element 1892 in the form of a Duff prism, wherein the rotatable optical element 1892 is configured to rotate to adjust the beam profile of a laser beam. A laser 1889 may be included in the laser system 1888. The laser 1889 can generate a laser beam having a first beam profile 1890A, and the laser 1889 can be configured to guide the laser beam toward a first surface 1892A of the rotatable optical element 1892 with the first beam profile 1890A. The laser 1889 can be configured to operate with characteristics similar to those used in other lasers described herein. An optical axis 1885 may be defined in the rotatable optical element 1892, wherein the optical axis 1885 extends between the first surface 1892A and a second surface 1892B. The optical axis 1885 may extend along a line extending approximately between the center of the first surface 1892A and the center of the second surface 1892B. In some embodiments, the laser beam can be received at the first surface 1892A with a small linear offset relative to the optical axis 1885. By doing so, the focused beam can be rapidly rotated about the axis of rotation in a circle while maintaining its orientation relative to the tangent of the circle.

[0226] The rotatable optical element 1892 includes a first surface 1892A and a second surface 1892B. The rotatable optical element 1892 is configured to receive a laser beam at the first surface 1892A, and is configured to allow the laser beam to pass through the rotatable optical element 1892 to the second surface 1892B, such that the laser beam has a second beam profile 1890B when exiting the second surface 1892B. After exiting at the second surface 1892B, the laser beam can be received at a sheet 1897, allowing a modification 1897A to be applied to the sheet 1897. The modification 1897A can be at least one of the following: perforation, refractive index modification, trenching, voids, densification, changes in chemical bonding in the material, melting, color centers, or internal features in the sheet 1897. However, other modifications can be formed in the sheet 1897. Figure 18A In the illustrated embodiment, modification 1897A is an internal feature in sheet 1897, and the internal feature has the same characteristics as... Figures 26A-26B The example shown has a similar cross-sectional edge shape that is symmetrical about the optical axis. Different segments of the sheet may be separated from each other near the location of the internal features. In some embodiments, sheet 1897 may comprise glass, but in other embodiments, sheet 1897 may comprise different materials. Figure 18AModification 1897A is not drawn to scale. Sheet 1897 can be positioned on motion platform 1899 such that sheet 1897 is generally held in a fixed position relative to motion platform 1899 during operation, and motion platform 1899 can move relative to other components of laser system 1888, so that modifications can be formed at different locations within sheet 1897.

[0227] The laser system 1888 also includes a rotary actuator 1895. The rotary actuator 1895 is configured to rotate the rotatable optical element 1892. When the laser beam is actively guided into the rotatable optical element 1892, the rotary actuator 1895 can rotate the rotatable optical element 1892, and this can cause the beam profile of the laser beam to rotate at the sheet 1897.

[0228] A rotary actuator 1895 is configured to rotate a rotatable optical element 1892 as indicated by arrow 1894A, and the rotary actuator 1895 can rotate the rotatable optical element 1892 by a first angle. When the rotary actuator 1895 rotates the rotatable optical element 1892, the resulting second beam profile 1890B can rotate relative to the first beam profile 1890A as indicated by arrow 1894B, wherein the second beam profile 1890B rotates relative to the first beam profile 1890A by a second angle. Beam profiles 1890A and 1890B are provided for illustrative purposes only, and beam profiles with different shapes can be used. The rotatable optical element 1892 can be configured such that the second angle is greater than the first angle. In other words, when the rotatable optical element 1892 rotates, the second beam profile 1890B rotates by an even greater amount. In some embodiments, the second angle can be at least about 1.5 times the first angle, at least about 1.75 times the first angle, at least about 2 times the first angle, at least about 2.25 times the first angle, or at least about 2.5 times the first angle. In some embodiments, the second angle can be from 1.95 to 2.05 times the first angle. Even under such rotation, laser propagation can remain consistent with the input.

[0229] Laser system 1888 does not include any additional elements between rotatable optical element 1892 and sheet 1897 or between laser 1889 and rotatable optical element 1892. However, in other embodiments, the additional elements described herein may be present between rotatable optical element 1892 and sheet 1897.

[0230] As an alternative to the rotatable optical element 1892 provided in the form of a Duff prism, other rotatable optical elements can be used. For example, in some embodiments, a k-mirror assembly can be used. While a Duff prism typically operates by refraction, a k-mirror assembly is a reflecting equivalent of a Duff prism. A k-mirror assembly can be advantageous for high-power lasers because, compared to a Duff prism, it can be manufactured with lower losses and a higher damage threshold. Additionally, a k-mirror assembly can introduce fewer aberrations into the beam compared to a Duff prism.

[0231] Figure 18B The image shows an example laser system 1801 using a k-mirror assembly 1810. Laser system 1801 includes a laser 1889, which can be coupled with… Figure 18A The laser is the same as that in the laser system 1888. The laser 1889 can generate a laser beam with a first beam profile 1890A, and the laser 1889 can be configured to guide the laser beam along an initial path 1802 toward the k-mirror assembly 1810.

[0232] The illustrated k-mirror assembly 1810 includes a first mirror 1812, a second mirror 1814, and a third mirror 1816. Additionally, in some embodiments, the k-mirror assembly 1810 may include a rotary actuator 1818, but in other embodiments, the rotary actuator 1818 may be separate from the k-mirror assembly 1810. Mirrors 1812, 1814, and 1816 may be angled such that the laser beam travels along an initial path 1802 parallel and / or collinear with the exit path 1808. Although mirrors 1812 and 1816 extend at equal but opposite angles, they may extend at various different angles. Furthermore, although mirror 1814 extends in a plane parallel to the initial path 1802 of the laser beam, the plane of mirror 1814 may extend at other angles. The illustrated k-mirror assembly 1810 is merely exemplary, and modifications to the k-mirror assembly are possible in other embodiments.

[0233] The laser beam travels along an initial path 1802 until it reaches the first mirror 1812 of the k-mirror assembly 1810. The laser beam traveling along the initial path 1802 is reflected by the first mirror 1812, causing it to travel along path 1804 towards the second mirror 1814. The laser beam traveling along path 1804 is reflected by the second mirror 1814, causing it to travel along path 1806 towards the third mirror 1816. Then, the laser beam traveling along path 1806 is reflected by the third mirror 1816, effectively exiting the k-mirror assembly 1810, causing it to travel along an exit path 1808. The laser beam traveling along exit path 1808 can produce a second beam profile 1890B.

[0234] Rotary actuator 1818 allows k-mirror assembly 1810 to rotate about a rotation axis, which can be parallel to the initial path 1802 and the exit path 1808 of the laser beam. As k-mirror assembly 1810 rotates, the beam profile of the laser beam also rotates. Similar to a Duff prism, rotation of the k-mirror assembly can allow a second beam profile 1890B to rotate at a faster rate than k-mirror assembly 1810 itself. When k-mirror assembly 1810 rotates by a first angle (as indicated by arrow 1820), the second beam profile 1890B can rotate by a second angle (as indicated by arrow 1822). In some embodiments, the second angle can be at least about 1.5 times the first angle, at least about 1.75 times the first angle, at least about 2 times the first angle, at least about 2.25 times the first angle, or at least about 2.5 times the first angle. Even with such rotation, laser propagation can remain consistent with the input.

[0235] A rotatable optical element in the form of a Duff prism was tested using a spatially asymmetric Airy beam. Figure 19-21 The properties of a non-rotating Airy beam were demonstrated, and Figure 22-24 The properties of an Airy beam rotated using a Duff prism are demonstrated. Figure 19 The figure from 1996 shows the longitudinal profiles of Airy beams at different Y-coordinates, and... Figure 20 Figure 2096 shows the longitudinal profiles of Airy beams at different X-coordinates. Figure 21 Figure 2196 shows the intensity profile at different locations along the propagation axis (in the Z-direction).

[0236] Figure 22 Figure 2296 shows longitudinal profiles of the Airy beam at different Y-coordinates, where the profiles have been compared to... Figure 19 The chart in the image is rotated 180 degrees, and Figure 23 Figure 2396 shows longitudinal profiles of the Airy beam at different X-coordinates, where the profiles are already relative to... Figure 20 The chart in the image is rotated 180 degrees. Figure 24 Figure 2496 shows the intensity profiles at different locations along the propagation axis (in the Z-direction), where the profiles have been relative to... Figure 21 The chart in the image is rotated 180 degrees.

[0237] In order to obtain Figure 22-24 The characteristics of the Airy beam were achieved using a laser system similar to the 1888 laser system, thus employing a Duff prism. In the laser system, the Duff prism is rotated approximately 90 degrees, causing the beam profile to rotate approximately 180 degrees at the sheet. For example, Figure 22 The beam profile shown in the image is relative to Figure 19The beam profile shown in the image is rotated approximately 180 degrees, and Figure 22 The position of the maximum value of the middle Airy beam relative to the y-coordinate is relative to Figure 19 The position in the middle is effectively flipped. Additionally, Figure 23 The beam profile shown in the image is relative to Figure 20 The beam profile is rotated approximately 180 degrees, and Figure 23 The position of the maximum value of the middle Airy beam relative to the x-coordinate is relative to Figure 20 The position in the middle is effectively flipped. However, even in this rotation, Figure 21 Chart 2196 and Figure 24 The intensity of the beam in Chart 2496 is actually the same.

[0238] Figure 25 Image 2598 shows an example laser perforation profile 2598B of an Airy beam. Image 2598 shows sheet 2598A, and the beam is used to separate segment 2598C of sheet 2598A. The edges have a slightly rounded outer corner shape, as... Figure 25 The image shows a cross-section of the Airy beam. In the case of laser perforation profile 2598B, a first peak 2506 and a second peak 2508 are formed at the edge, with a distance 2504 between the two peaks of approximately 20 micrometers. This laser perforation profile 2598B was produced using an Airy beam that was not optimized for cut quality, and other laser perforation profiles with improved quality can be obtained using other techniques described herein.

[0239] Optical systems can be used to rotate a desired laser beam profile to track a specific orientation relative to the shape of a given part. These optical systems can also be used to generate internal features by following a similar path when the beam orientation is reversed. A notable example is the rapid generation of internal features.

[0240] exist Figures 26A-26B The image shows several examples of internal features that can be produced in a sheet, where the internal features have edge profiles defined by laser profiles. Figures 26A-26B In each of the schematic diagrams shown, an optical axis 2603 is illustrated, and the corresponding beam profile is ultimately rotated about the optical axis 2603 to form an internal feature.

[0241] In schematic diagram 2601A, a beam profile 2605A relative to the optical axis 2603 is shown. The beam profile 2605A has a concave, curved shape and is positioned close to the optical axis 2603 near its center. In schematic diagram 2601B, a laser beam with beam profile 2605A is used to form an internal feature in sheet 2607. The beam profile 2605A is rotated relative to the optical axis 2603, as indicated by arrow 2609, to form the internal feature. The internal feature has a narrow central processing area that propagates towards the top and bottom of sheet 2607.

[0242] In schematic diagram 2601C, a beam profile 2605B relative to the optical axis 2603 is shown. The beam profile 2605B has a similar... Figure 26A The beam profile 2605A has a concave curved shape, but relative to Figure 26A The laser beam has beam profiles 2605A and 2605B positioned away from the optical axis 2603. In schematic diagram 2601D, the laser beam with beam profile 2605B is used to form an internal feature in sheet 2607. Beam profile 2605B is rotated relative to the optical axis 2603 as indicated by arrow 2609 to form the internal feature, and the internal feature has an hourglass shape having a wider minimum thickness relative to the shape formed in schematic diagram 2601B.

[0243] In schematic diagram 2601E, a beam profile 2605C relative to the optical axis 2603 is shown. The beam profile 2605C has a convex curved shape, wherein the beam profile 2605C is closer to the optical axis 2603 at its edges than at its center. In schematic diagram 2601F, a laser beam with beam profile 2605C is used to form an internal feature in sheet 2607. The beam profile 2605C is rotated relative to the optical axis 2603 as indicated by arrow 2609 to form the internal feature, and the internal feature has a wider thickness near the center of sheet 2607 and a smaller thickness near the edges of sheet 2607.

[0244] In schematic diagram 2601G, a beam profile 2605D relative to the optical axis 2603 is shown. Beam profile 2605D has multiple linear segments. In schematic diagram 2601H, a laser beam with beam profile 2605D is used to form an internal feature in sheet 2607. Beam profile 2605D is configured to form a C-shaped beveled edge. As used herein, a “C-shaped beveled edge” is a multi-segmented angled beveled edge having multiple generally flat surfaces, and in some embodiments, these edges may include three surfaces. Beam profile 2605D is rotated relative to the optical axis 2603 as indicated by arrow 2609 to form the internal feature, and the internal feature has a wider thickness near the center of sheet 2607 and a smaller thickness near the edges of sheet 2607.

[0245] Although Figures 26A-26B The diagram shows various shapes for the cross-sectional edge of the internal features, but other cross-sectional edge shapes, such as parabolic shapes, polygonal shapes, or shapes containing multiple linear segments, can also be used. Other cross-sectional edge shapes are also possible.

[0246] Chemical strengthening of glass, such as through ion exchange, is a way to obtain stronger and more reliable components for cover glass used in displays or handheld devices. In ion exchange, glass sections can be immersed in a salt bath, and this immersion allows larger ions to penetrate the surface of the glass sheet to form a thin, compressed layer near the sheet surface.

[0247] like Figures 26A-26B The internal features shown can be used to create a series of perforated profiles, forming removable sections within the sheet. However, internal features can also be used to strengthen the glass at the sheet level by allowing ion-exchange materials to penetrate and diffuse within the internal features to form compression zones before the internal sections are removed.

[0248] Depending on the specific application, these internal features can be retained within the sheet. In this case, the internal features allow ion-exchange materials to easily penetrate at the internal features, thereby forming a compression zone. In some embodiments, the internal features can be mechanically adjusted to form larger holes, or the features can be wet-etched (e.g., to form shaped through-holes in the glass). In addition to providing internal or external contour parts with shaped edge geometry, small circular features with initially shaped geometry (bent, beveled, angled, etc.) can be used to increase the aspect ratio of the etched through-holes in the glass, or to facilitate the retention or removal of glass plugs. These glass plugs are small portions of the glass sheet that perforate other sheets when some internal features are formed. Combining the rotation of a direct laser beam or a shaped laser beam with laser perforation (continuous laser emission during sample translation) allows for the high-speed formation of corrugated, fan-shaped, or other complex edge geometries.

[0249] The previous solution presented a trade-off when attempting ion exchange. Cutting the sheet into individual segments and separating these segments from the sheet before ion exchange allows for high edge strength on each part due to ion exchange along the entire part edge; however, this also necessitates a more complex and less cost-effective treatment of all individual parts. In this approach, individual parts must be treated separately for each segment for all post-cutting steps (such as ion exchange, cleaning, coating application (e.g., inks, other printing features, dielectric coatings such as anti-reflective coatings, polymers, anti-fingerprint coatings, etc.)). Individual part treatment and coating are typically more expensive than applying the same process across the entire sheet.

[0250] In another alternative solution, ion exchange processing can be performed across the entire sheet before perforation. This simplifies sheet handling compared to processing separated sections independently. Additionally, coating application is simpler on larger sheets when ion exchange processing is performed across the entire sheet. However, since individual sections must be cut from the sheet after ion exchange processing, the edge strength of the cut edges may be lower due to the lack of ion-exchange material along the cut edges.

[0251] To address these trade-offs, these processes can be performed in different sequences. Perforations can be formed within the sheet before any ion-exchange processing. However, the segments defined by the perforations within the sheet can remain within the sheet. Even if a segment pops out, it can be considered to remain within the sheet, only ceasing to be retained when the segment is completely removed from the sheet. The entire sheet, including any removable segments, can be subjected to ion exchange and other processing before actual removal of the removable segments. This approach can provide greater efficiency in ion-exchange processes because processing can be performed at the entire sheet level, making the handling of the sheet and its removable segments less difficult and more efficient, and realizing the other benefits of operating at the entire sheet level. However, since the ion-exchange material can penetrate the laser perforations, the sheet and its removable segments can also have improved edge strength, thus reinforcing the edges along their entire length. Edge strength can be greater than about 500 MPa or even greater than about 600 MPa, and these edge strengths can be achieved across a range of glass thicknesses (e.g., between about 0.2 mm and about 1.3 mm).

[0252] Scanning microprobe data of potassium ion concentration at the edges of the glass samples were evaluated to ensure effective diffusion of the ion exchange material in this novel process flow, and the scanned microprobe data confirmed complete penetration of the ion exchange material through the perforations. Furthermore, minimal brush polishing on the final monocut parts (typically removing less than approximately 20 micrometers of material at the edges) can be used to increase edge strength to greater than approximately 800 MPa while still maintaining a compression zone of the ion exchange material on all surfaces of the formed segment, since the removal depth can be less than the DOL of the compression zone of the ion exchange material.

[0253] Figures 27A-27B The diagram illustrates a process flow for forming ion-diffused edges of perforations in a sheet. At stage 2702A, a sheet 2704 is provided, and perforations 2706 with desired profiles (e.g., laser perforation) are formed in the sheet 2704. Various profiles with different shapes and sizes can be used. After forming the perforations 2706, a segment 2708 that can be separated from another frame portion of the sheet 2704 can be formed in the sheet 2704. However, the segment 2708 can remain within the sheet 2704 and cannot be separated from the sheet 2704 until later in the process flow.

[0254] Perforation can create through-body defects in glass sheets, which can guide crack propagation. When perforation is used to create an internal profile, the segment can be retained within the sheet. This allows for complete sheet processing during the ion exchange, washing, and coating stages. Retaining the removable segment within the sheet also allows the final cut segment to have the edge strength that realizes the benefits derived from ion exchange, exceeding 500 MPa. Furthermore, as further described herein, brush polishing can be performed after ion exchange to produce parts with edge strengths exceeding 800 MPa.

[0255] At stage 2702B, sheet 2704 is exposed to an ion-exchange material, which may be provided in bath 2710. Sheet 2704 may be placed in bath 2710 such that the ion-exchange material can diffuse into sheet 2704. Specifically, the ion-exchange material can diffuse into sheet 2704, diffuse into segment 2708, and can penetrate perforation 2706 such that the edges of segment 2708 are exposed to the ion-exchange material. Thus, perforation 2706 can serve as a channel for the ion-exchange material.

[0256] Bath 2710 may be a molten salt bath (or two or more molten salt baths) containing larger ions to be exchanged with smaller ions in sheet 2704. It should be noted that aqueous salt baths may also be used. Additionally, the bath composition may contain more than one type of larger ion (e.g., Na+ and K+) or a single larger ion. Those skilled in the art will understand that the parameters of the ion exchange process, including but not limited to the bath composition and temperature, immersion time, number of immersions of sheet 2704 in one or more salt baths, use of multiple salt baths, and additional steps (such as annealing, washing, etc.), can generally be determined by the composition of sheet 2704, the desired layer depth, and the surface compressive strength of sheet 2704 resulting from the strengthening process. Exemplary molten bath compositions may contain nitrates, sulfates, and chlorides of larger alkali metal ions. Typical nitrates include KNO3, NaNO3, LiNO3, NaSO4, and combinations thereof. The temperature of bath 2710 is typically in the range of approximately 380 degrees Celsius to approximately 500 degrees Celsius, while the immersion time depends on the thickness of sheet 2704, the bath temperature, and the glass (or monovalent ion) diffusivity of sheet 2704, and can range from approximately 15 minutes to approximately 100 hours. However, temperatures and immersion times different from those described above may also be used.

[0257] In various embodiments, the sheet 2704 may be immersed in a molten salt bath of 100% NaNO3, 100% KNO3, or a combination of NaNO3 and KNO3 at a temperature of about 370 degrees Celsius to about 500 degrees Celsius. In some embodiments, the sheet 2704 may be immersed in a molten mixed salt bath containing about 5% to about 90% KNO3 and about 10% to about 95% NaNO3. In one or more embodiments, after immersion in the first bath, the sheet 2704 may be immersed in a second bath. The first and second baths may have different compositions and / or temperatures. The immersion times in the first and second baths may differ. For example, the immersion in the first bath may be longer than the immersion in the second bath. In various embodiments, the sheet 2704 may be immersed in a molten mixed salt bath containing NaNO3 and KNO3 (e.g., 49% / 51%, 50% / 50%, 51% / 49%) at a temperature of less than about 420 degrees Celsius (e.g., about 400 degrees Celsius or about 380 degrees Celsius) for less than about 5 hours, or even about 4 hours or less.

[0258] Once the ion exchange is complete, the sheet 2704 can be removed from the bath 2710. Therefore, the resulting segment 2708 formed by the sheet 2704 includes a compression zone containing ion exchange material on the outer surface of the segment 2708.

[0259] Ion exchange processes can be used for chemically strengthened glass substrates and other materials. The bath 2710 of the ion exchange material may contain a molten salt, and larger base ions from the bath 2710 can diffuse into the sheet 2704 (typically K+) and replace smaller base ions. For example, the larger base ions may be potassium ions (K+), and these ions may be configured to replace sodium ions (Na+) or other ions, wherein the sheet 2704 comprises glass. However, in other embodiments, the ions that diffuse into the substrate during ion exchange and the ions that are replaced during ion exchange may be different.

[0260] During ion exchange, the penetration of larger ions introduces compressive stress to the surface and edges of the sheet, potentially making the sheet more resistant to surface damage and resulting cracks. Ions typically diffuse into any part of the sheet that is in direct contact with the salt bath. The distance ions diffuse into the sheet is typically characterized by DOL (Diffusion Occurrence Limit). The penetration of larger diffused ions causes compression in areas close to the sheet surface. Therefore, for sheets, the large, flat surfaces and exposed edges become reinforced. Typical edge strength for such ion-exchanged sheets is approximately 600 MPa, where the precise value depends on the material, the amount of ion exchange processing performed, and the precision of the finish applied to the glass edges.

[0261] Even though some processes, such as laser perforation, can be used to cut sheets after ion exchange, this method has drawbacks. When a sheet is perforated and / or cut after ion exchange, any perforated edges formed during the laser perforation process are not exposed to any salt bath during ion exchange. Therefore, the ion-exchange material is typically not present at the edges of these newly perforated areas, resulting in weaker edge strength. In some cases where ion exchange is performed before laser perforation, the edge strength of the newly perforated edges may be approximately one-fifth to one-quarter of the edge strength of parts that were perforated first and then ion-exchanged.

[0262] Looking back Figure 27A In state 2702C, sheet 2704 can be printed or decorated in other ways. Figure 27B At stage 2702D, segment 2708 can be cut from the frame of sheet 2704. This can be achieved by forming release lines 2712 in the frame of sheet 2704 using laser or mechanical scribing, which cause the sheet to separate segment 2708 from the rest of sheet 2704. Because sheet 2704 is ion-exchanged, there is a significant amount of internal stress (central tension) throughout the sheet, which causes the glass sheet to separate rapidly around release lines 2712.

[0263] At stage 2702E, segment 2708 is shown separated from sheet 2704. A compression zone containing ion-exchange material may be present at the edge of segment 2708 to give segment 2708 and its edges greater strength. In some embodiments, the segment may be polished after ion exchange is complete.

[0264] After the sheet is perforated to form segments, the segments may pop out prematurely before they are intended to separate from the rest of the sheet. Due to stress generated by ion exchange, cracks can propagate along the internal contour after ion exchange, causing the segment to become physically disconnected from the surrounding frame. When such a sheet is bent or vibrated, these segments can shift slightly out of the sheet's plane, causing them to tilt slightly and protrude a certain distance relative to the surrounding frame, such as about 10 micrometers or more, about 50 micrometers or more, or about 500 micrometers or more. In extreme cases, the segment may detach completely from the surrounding sheet. As the sheet increases to larger dimensions, such as sheets larger than about 475 mm by 750 mm, or even larger than about 730 mm by 920 mm, popping becomes more frequent and larger in magnitude.

[0265] Figure 29 The diagram illustrates an example of a pop-up, in which... Figure 28 This shows a similar section 2804 before the pop-up. Figure 28In this structure, segment 2804 is positioned within frame 2802 of sheet 2800. Sheet 2800 has laser-perforated edges 2806 of the inner segment that separate segment 2804 from frame 2802. Sheet 2800 also has a thickness T1, and this thickness T1 can remain relatively uniform across the entire sheet 2800. Furthermore, the thickness T1, the dimensions of segment 2804, and the shape of the laser-perforated edges 2806 affect the force required to pop or release segment 2804. Once the perforated edges 2806 are formed in sheet 2800, segment 2804 can remain in close contact with frame 2802, so that after the laser-perforated edges 2806 are formed, segment 2804 will not simply detach from the parent sheet due to friction between segment 2804 and frame 2802 and the texture of the perforated edges 2806 of segment 2804 and frame 2802. In the various embodiments described herein, the average surface roughness of the edges of the segments formed within the sheet can be less than or equal to about 5 micrometers, or even less than or equal to about 1 micrometer. In the case of brush polishing, the average surface roughness can be about 100 nanometers or less, about 20 nanometers or less, or even about 10 nanometers or less. After ion exchange, a larger gap can be formed near the edge 2806 of the laser-perforated area.

[0266] However, if the force acting on segment 2804 is greater than the frictional force that holds segment 2804 in place, then segment 2804 may experience popping. Popping may occur if sheet 2800 is bent, if sheet 2800 is subjected to vibration or other repetitive motion, or if other forces act directly on segment 2804 or frame 2802. Popping may also occur when salt is washed off the sheet (e.g., after ion exchange), when the sheet is immersed in hot water during an immersion-rinse event, or when subjected to a thermal gradient, or during transport, or during washing. Other causes of popping may also exist.

[0267] Figure 29 This is a diagram illustrating the process of segment 2904 being popped up. Figure 29 In the middle, sheet 2900 includes a frame 2902 and a segment 2904, wherein segment 2904 is separated from frame 2902 through perforations 2906. Figure 29 In the middle, segment 2904 protrudes relative to frame 2902 at the upper right corner and lower left corner of segment 2904, and segment 2904 rotates relative to frame 2902.

[0268] Popping is generally not a problem before the ion exchange process is complete, as the internal sections remain connected to the surrounding frame. However, popping tends to become more problematic after the ion exchange process is complete. The ion exchange process can generate sufficient stress within the sheet to cause cracks to propagate around the edges of the internal sections. In itself, this crack propagation is not a problem, as cracks tend to run along the edges of the internal parts. However, subsequent bending or vibration of the sheet during sheet transport or washing can cause the internal sections to slide relative to the frame and protrude from the sheet.

[0269] Figure 30 This diagram shows the height of sheet 3000 at different locations, where sheet 3000 undergoes a pop-out at the edge of segment 3004. Sheet 3000 has six segments 3004 positioned within it, and the sheet 3000 measures approximately 475 mm by 750 mm. Sheet 3000 also includes a frame 3002 surrounding the segments 3004, and perforations 3006 separate the segments 3004 from the surrounding frame 3002. Sheet 3000 undergoes laser perforation, ion exchange, impregnation-rinsing, and is then transported to a height measurement system.

[0270] In the event of a pop-out, the internal section typically protrudes outward from the rest of the sheet by up to approximately 100 micrometers (or 0.1 millimeters). However, for Figure 30 In the examples shown, the pops are even more pronounced in some locations. While the height at the edge of segment 3004 is generally between approximately -0.05 mm and approximately 0.05 mm in most locations, in segments 3008, 3010, and 3012, the height at the edge of segment 3004 falls outside this range. In segment 3008, the height reaches approximately 0.23795 mm. In segment 3010, the height reaches approximately -0.080 mm, and in segment 3012, the height reaches approximately -0.0888 mm. Such a large number of pops can be harmful for the reasons mentioned herein.

[0271] Figure 31 This is a schematic diagram showing an example segment 3104 positioned within sheet 3100, where the edge 3106 of a straight laser-perforated section separates sheet 3100 from its surrounding frame 3102. Vertical movement of segment 3104 is possible using sheet 3100, as indicated by arrow A1. However, since there is no gap (or a very small gap) between segment 3104 and the surrounding frame 3102, sheet 3100 must be subjected to bending or other forces to overcome the friction between segment 3104 and the surrounding frame 3102, thereby separating segment 3104 from the frame 3102.

[0272] Figure 32This is a schematic diagram illustrating an example segment 3204 separated from the surrounding frame 3202 of sheet 3200 by the edge 3206 of a nonlinear laser-perforated hole. The edge 3206 of the nonlinear laser-perforated hole is curved in shape, but in other embodiments, the edge of the nonlinear laser-perforated hole can be configured to have other shapes. Vertical movement of segment 3204 is possible using sheet 3200, as indicated by arrow A2. However, there is no macroscopic gap (or a very small gap) between segment 3204 and the surrounding frame 3202, so segment 3204 remains within the frame 3202 of sheet 3200. Sheet 3200 must be subjected to bending or other forces to separate segment 3204 from frame 3202. Due to the shape of the edge 3206 of the nonlinear laser-perforated hole, the amount of force required to eject segment 3204 is greater than the amount of force required to eject segment 3104.

[0273] Sheet 3200 includes a first surface 3214 and a second surface 3216 opposite to the first surface 3214. The two surfaces 3214 and 3216 extend parallel to the XY plane. Edges 3206 of nonlinear laser perforations extend between the first surface 3214 and the second surface 3216, wherein the edges 3206 of the nonlinear laser perforations are positioned between segments 3204 of the frame 3202 of the sheet 3200. These edges 3206 of the nonlinear laser perforations form one or more internal edges. The edges 3206 of the nonlinear laser perforations can be formed by various types of laser beams, such as caustic laser beams, bent Bessel beams, or other laser beams. In sheet 3200, a first direction D1 extends parallel to the Z-axis, wherein the first direction D1 is perpendicular to a first plane and a second plane. A second direction D2 extends parallel to the X-axis and perpendicular to the first direction D1.

[0274] Sheet 3200 has one or more inner edges 3218 formed therein, adjacent to the edge 3206 of a nonlinear laser-perforated sheet. The inner edges 3218 have a nonlinear profile with a vertex 3212, and extend between a first corner 3208 and a second corner 3210. The first corner 3208 connects a first surface 3214 and the inner edge 3218, and the second corner 3210 connects a second surface 3216 and the inner edge 3218. Compared to the first corner 3208 and the second corner 3210, the inner edge 3218 extends further in the second direction D2 at the vertex 3212. Figure 32In this embodiment, vertex 3212 extends a further distance B1 in the second direction D2 relative to either the first corner 3208 or the second corner 3210 (whichever corner is farther). This distance B1 may be referred to herein as the "vertex distance". In some embodiments, vertex distance B1 may be at least about 3 micrometers, at least about 5 micrometers, at least about 10 micrometers, at least about 20 micrometers, at least about 40 micrometers, or even at least about 60 micrometers. Sheet 3200 includes material diffused by ion exchange, wherein the diffused material is positioned along the first surface 3214, the second surface 3216, and the inner edge 3218. Vertex distance B1 may be greater than or equal to DOL of the ion-exchange material diffused on the surface of segment 3204. Figure 32 In this embodiment, the inner edge 3218 has a curved shape, but in other embodiments, the inner edge may be configured to have multiple flat surfaces (e.g., a C-shaped beveled edge) or may have other shapes.

[0275] A contact angle θ3 is defined at a segment 3204 between a line perpendicular to the first surface 3214 and a portion of the edge surface 3218 immediately adjacent to the first corner 3208. In some embodiments, the contact angle θ3 may be at least about 10 degrees or greater, about 12.5 degrees or greater, about 15 degrees or greater, about 17.5 degrees or greater, or about 20 degrees or greater. An angle similar to the contact angle θ3 may be defined at a second corner 3210 between a line perpendicular to the second surface 3216 and a portion of the edge surface 3218 immediately adjacent to the second surface 3216. The contact angle can be measured by obtaining the angle between a line perpendicular to the surface 3214 and a line tangent to the edge surface 3218 at the corner 3208.

[0276] Similar to Figure 43The sections shown, including sheet 3200 and section 3204, may include diffused material that has been diffused by ion exchange, wherein the diffused material is positioned along a first surface 3214, a second surface 3216, and an edge surface 3218. In some embodiments, potassium ions may be used during the ion exchange process to create a compression zone containing residual potassium in sheet 3200. The diffused ion-exchange material may help form a compression zone at one or more locations on sheet 3200 that extends fully from the first surface 3214 to the second surface 3216. For example, the compression zone may extend all the way through the edge 3206 of the nonlinear laser-perforated area between surfaces 3214 and 3216. In some embodiments, the DOL of the compression zone at edge surface 3218 may be about 5 micrometers or larger. However, if the edge surface has been polished after the ion exchange process, the DOL of the compression zone at edge surface 3218 may be smaller than the DOL of the compression zone at the first surface 3214. For example, in some embodiments, the compression zone at the edge surface 3218 may be at least about 5 micrometers smaller than the DOL of the compression zone at the first surface 3214. Alternatively, the surface concentration of the ion exchange material in the compression zone at the edge surface 3218 may be less than the surface concentration of the ion exchange material in the compression zones at the first surface 3214 or the second surface 3216. The vertex distance B1 may be equal to or greater than the DOL of the compression zone at the first surface 3214 or the second surface 3216.

[0277] Alternatively or additionally, one or more coatings may be present on the sheet 3200, and the coatings may comprise at least one of ink, dielectric coating, antireflective layer, metal, or polymer. In some embodiments, the sheet 3200 may comprise glass, but the sheet 3200 may comprise other materials.

[0278] The individual surfaces 3214, 3216, and 3218 of sheet 3200 may also have specific surface roughnesses. In some embodiments, if edge surface 3218 is not polished after ion exchange, the average surface roughness of edge surface 3218 may be less than about 5 micrometers, as measured by average surface roughness (Ra). When edge surface 3214 has been polished, the average surface roughness of the edge surface may be less than or equal to about 100 nanometers, about 20 nanometers, or even about 10 nanometers. However, in other embodiments, the average surface roughness may be different.

[0279] Quasi-diffraction-free beams are often referred to as “Bessel-like” laser beams, “Bessel” laser beams, or “focal lines.” When using lasers to cut glass, high-intensity, short-pulse lasers can be focused onto a spot diameter of approximately a few micrometers to modify the sheet material, inducing changes in refractive index, structural modifications, and / or microcracks. With conventional Gaussian-like laser beams, diffraction typically causes the light to propagate rapidly, meaning that such spot diameters remain constant only over propagation distances of tens of micrometers. However, Bessel-like beams maintain this focused spot size for propagation distances of millimeters or longer. This means that Bessel-like beams can rapidly produce controlled perforations, or laser-modified elongated lines of material, each of which extends through the total thickness of the glass sheet.

[0280] To cut glass sheets, perforations can be closely spaced, typically ranging from about 1 micrometer to about 50 micrometers apart. The perforations can be arranged to outline desired sections within the sheet. Closely spaced perforations can be used to generate and guide cracks formed by laser damage applied to the brittle material of the sheet. Therefore, the sheet can be separated around the perforated outline. Because the perforations penetrate the total thickness of the glass sheet, cracking can be reliably controlled even in high-stress materials. Furthermore, the fact that each laser beam emission causes a modification across the entire thickness means that cutting speeds can be very high (e.g., greater than about 1 meter per second).

[0281] Figure 33 This is a schematic diagram illustrating an example Bessel beam optics assembly 3300. Using this assembly 3300, an initial laser beam 3302A is guided toward a first optical element 3304 in the form of an axial cone, thereby generating a modified beam 3302B. The modified beam 3302B is then guided from the first optical element 3304 to a second optical element 3306, thereby generating a modified beam 3302C. The modified beam 3302C is then guided from the second optical element 3306 to a third optical element 3308, thereby generating a modified beam 3302D. The modified beam 3302D is then guided from the third optical element 3308 to a sheet 3312, wherein when the modified beam 3302D reaches the sheet 3312, it has a line focus 3310. The line focus 3310 can be adjusted based on the optical elements 3304, 3306, and 3308 used.

[0282] Figure 34This is graph 3400, showing an example intensity profile of a Bessel beam as a function of focal position. Focal positions are in millimeters, and peak-axis intensity is in analog-to-digital converter counts. As shown, the peak-axis intensity remains at approximately 0 counts until a focal position of approximately 0.6 mm is reached. The peak-axis intensity moves to approximately 240 counts at a focal position of approximately 1.1 mm, and then drops to approximately 0 counts at a focal position of approximately 2.0 mm.

[0283] Figure 35 Image 3500 shows an example cross-section of a Bessel beam, where the x-positions on the x-axis are in micrometers and the y-positions on the y-axis are in micrometers. The intensity of a Bessel beam is typically maximum at its center point, which is located at approximately 5 micrometers in the x-axis and approximately 5 micrometers in the y-axis. While the center point in image 3500 may appear darker than some of the surrounding points, this is an illusion caused by using a grayscale image, and the intensity is actually maximum at this center point. However, other color variations at locations far from this center point represent small sidelobes representing localized increases in intensity of the Bessel beam.

[0284] Using Bessel beams, elongated laser modifications can be achieved, and Bessel beams can effectively guide cracks within sheets. Furthermore, the lasers used to form Bessel beams are readily available, and these lasers can generate short-pulse, high-energy laser beams. Figure 36 This is a schematic diagram illustrating an example Bessel beam optics assembly 3600 including an axis cone 3604. A laser beam 3602 is guided to the axis cone 3604, which can guide the Bessel beam 3606 toward a sheet 3608. A focal line 3610 is also shown, and the length of the focal line 3610 can be greater than about 2 millimeters. Using a Bessel beam, a spot diameter of about a few micrometers (e.g., about 0.2 micrometers to about 5 micrometers) can be maintained over the total thickness of the sheet 3608. Perforations can be formed using the assembly 3600 with a laser configured to generate a laser beam with pulses having a pulse duration of about picoseconds.

[0285] Figure 37 It demonstrates the use and Figure 36 The figure shows a top view of a Bessel beam optics assembly similar to the one shown, with a perforation 3704 formed within sheet 3700. Sheet 3700 includes two distinct portions 3702 formed on opposite sides of the perforation 3704. One of these portions 3702 may be a removable segment, and the other may be a frame from which the removable segment can be separated. As shown, the perforation 3704 can guide crack propagation, with crack 3706 extending along the path formed by the perforation 3704.

[0286] Figure 38 It demonstrates the use of something similar to Figure 36 The image shows a front view of a Bessel beam optics assembly with a cut edge 3806 formed within sheet 3800. Sheet 3800 defines a thickness T2 measured from a first surface 3802 of sheet 3800 to an opposite second surface 3804 of sheet 3800, where thickness T2 is approximately 700 micrometers. However, in other embodiments, the thickness T2 value may be different. The cut edge 3806 extends between the first surface 3802 and the second surface 3804. As can be seen on the cut edge 3806, the formed perforation typically occurs within... Figure 38 It extends vertically in the middle.

[0287] Traditionally, laser cutting has been used to create straight glass edges. If a beveled edge is desired at the glass edge, this is typically accomplished by mechanically grinding or polishing the glass edge after cutting using a grinding wheel whose shape is configured to apply the desired edge shape.

[0288] In the case of perforation, a nominally straight Bessel-like beam can be modified into other beams to create nonlinear perforations. For example, multi-segment angled Bessel beams (including quasi-diffraction-free beams with stitched, straight, and angled Bessel beam facets) can be used to produce C-bevel shapes, or curved beams can be used to produce curved bevel shapes. Laser beams exhibiting curved focusing regions include, but are not limited to, caustic beams, Airy beams, or curved Bessel beams. In the case of curved beam profiles, Airy beams can be used for lower contact angle bevels (typically less than about 15 degrees), while caustic or curved Bessel beams can be used to produce higher contact angle bevels. Figures 39A-39B Examples of glass edges with nonlinear perforations are shown. The perforation methods used to form these edges can retain many of the benefits of direct perforation cutting, such as the ability to cut arbitrary two-dimensional shapes, easy segment separation, and low defect size.

[0289] Figure 39AThe side sectional view shows the cut edge of an example segment 3900 of the sheet material, where a C-shaped beveled edge is formed by laser perforation using multiple angled Bezier beams. Segment 3900 includes an edge having an edge surface 3922, and edge surface 3922 includes a first portion 3902, a second portion 3906, and a vertex portion 3904 positioned between the first portion 3902 and the second portion 3906. Segment 3900 also has a first surface 3908 and a second surface 3918 opposite to the first surface 3908. Surfaces 3908 and 3918 are parallel to each other. Corner 3920 connects the first surface 3908 and edge surface 3922, and corner 3924 connects the second surface 3918 and edge surface 3922. The thickness of segment 3900 containing glass is approximately 0.7 mm, where this thickness is measured as the minimum distance from the first surface 3908 to the second surface 3918.

[0290] Different portions of edge surface 3922 extend at different angles. Vertex portion 3904 typically extends as a flat surface, where this surface extends at a 90-degree angle relative to surfaces 3908 and 3918. Although vertex portion 3904... Figure 39A The surface is flat, but the vertex portion 3904 can simply be the point or tip that extends furthest relative to the other portions of the edge surface, or the vertex portion can be configured to have another shape. The first portion 3902 extends at a contact angle θ5 relative to a line perpendicular to the first surface 3908, and the second portion 3906 extends at a contact angle θ4 relative to a line perpendicular to the second surface 3918. In some embodiments, angles θ4 and θ5 can be equal to each other. In some embodiments, angles θ4 and θ5 can be about 10 degrees or greater, about 12.5 degrees or greater, about 15 degrees or greater, about 17.5 degrees or greater, or about 20 degrees or greater. The contact angles can each be measured at one of the corners 3920 and 3924.

[0291] To achieve high-quality cutting, it can be beneficial to pay special attention to certain aspects of beam formation and maintain certain conditions. If these conditions are not met, the glass separation may deviate from the intended chamfer shape. For example, when forming a C-shaped beveled edge, multiple angled Bezier beams may experience off-axis aberrations, and phase mask-based correction methods can be used to compensate for aberrations in the lens system and in the light rays entering the glass at a specific angle. This can be achieved by applying a precise amount of spherical aberration to the beam, where the aberrations may differ near the top, middle, and bottom segments of the beam.

[0292] Additionally, the multi-segment angled Bessel beams require both lateral and offset compensation for each beam segment to ensure precise stitching of each beam to the glass substrate. This can be achieved by introducing small-angle and lateral offsets applied independently to each segment of the beam in the phase mask. The three beam segments can also be decoherence-based to prevent interference between each beam segment and adjacent beams at their intersections or slight overlaps, and this can be achieved by altering the polarization of each beam segment (e.g., by using a cut-out waveplate that only affects the middle segment of the three beams).

[0293] To generate multi-segment angled Bessel beams, various beam parameters can be used. A laser beam with a wavelength of approximately 1030 nanometers can be generated. Alternatively, the laser beam can be generated in the form of pulse bursts, with each burst consisting of 4 pulses and a pulse width of approximately 9 picoseconds. A pulse delay of 25 nanoseconds can be used between each pulse. Approximately 160 microjoules of energy are delivered to the sheet in each burst. The laser beam generates perforations with a spacing of approximately 3 micrometers between adjacent perforations and a spot diameter of approximately 3 micrometers. Additionally, the values ​​for the lengths of the top, middle, and bottom beam segments can be similar to... Figure 41C The values ​​shown are not provided. While this paper describes certain beam parameters, other beam parameters can also be used to generate multi-segment angled Bessel beams. Although multi-segment angled Bessel beams are advantageous in many ways, forming high-angle chamfers with contact angles of approximately 20 degrees or greater can be challenging for multi-segment angled Bessel beams. Additionally, the fabrication of the optics used to generate these multi-segment angled Bessel beams can be challenging. For example, fabricating the phase mask and achieving the ultimate goal of generating multi-segment angled beams with high contact angles can be challenging.

[0294] Figure 39B This is a side cross-sectional view showing the cut edge of an example section 3910 of the sheet, which shows a curved beveled edge formed by laser perforation using an Airy laser beam. Figure 39BThe right and left sides of the image show the same segment 3910. Segment 3910 includes an edge having an edge surface 3934, and the edge surface 3934 includes a first portion 3912, a second portion 3916, and a vertex 3914 positioned between the first portion 3912 and the second portion 3916. Segment 3910 also has a first surface 3926 and a second surface 3930 opposite to the first surface 3926. Surfaces 3926 and 3930 are parallel to each other. Corner 3928 connects the first surface 3926 and the edge surface 3934, and corner 3932 connects the second surface 3930 and the edge surface 3934. Segment 3910 contains glass and has a thickness of approximately 0.55 mm, where this thickness is measured as the minimum distance from the first surface 3926 to the second surface 3930.

[0295] and Figure 39A Vertex 3904 is different from vertex 3914, which is simply... Figure 39B The point where the first portion 3912 and the second portion 3916 of the middle edge surface 3934 intersect, but this vertex 3914 can extend to... Figure 39B The first portion 3912 extends with a contact angle θ6 relative to a line perpendicular to the first surface 3926, and the second portion 3916 extends with a contact angle θ7 relative to a line perpendicular to the second surface 3930. Contact angles θ6 and θ7 can be measured at one of the corners 3928 and 3932. In some embodiments, contact angles θ6 and θ7 can be equal to each other. In some embodiments, contact angles θ6 and θ7 can be about 10 degrees or greater, about 12.5 degrees or greater, about 15 degrees or greater, about 17.5 degrees or greater, or about 20 degrees or greater.

[0296] Various beam parameters can be used to generate Airy laser beams, or essentially Airy-like laser beams. Laser beams with wavelengths of approximately 1030 nanometers can be generated. Alternatively, the laser beam can be generated in the form of pulse bursts, with each burst consisting of 8 pulses and a pulse width of approximately 9 picoseconds. A pulse delay of 25 nanoseconds can be used between each pulse. Approximately 230 microjoules of energy are delivered to the sheet in each burst. The laser beam generates perforations with a spacing of approximately 12 micrometers between adjacent perforations and perforations with a spot diameter of approximately 3 micrometers. Additionally, the beam length, measured in air, is approximately 765 micrometers. However, other beam parameters can be used to generate Airy laser beams.

[0297] Certain beamforming techniques may be advantageous when using Airy beams to create curved, beveled edges. The incident beam on the phase mask can be applied in an elliptical shape with a major-to-minor axis ratio of approximately 8:1. Using this elliptical shape reduces the amplitude of the side lobes of the focused beam. Excessively high side lobe intensity can cause damage at unintended locations in the sheet, and this side lobe laser damage may prevent the separation of removable sections from being fully guided by laser damage from the main lobe of the beam as intended.

[0298] Additionally, Airy laser beams can function more effectively in high burst modes. In these high burst modes, there may be up to eight or more pulses in each burst, and this can reduce damage from sidelobes, including first-order sidelobes, which are the strongest. Similarly, such sidelobe damage can potentially prevent the separation of removable segments from laser damage originating from the main lobe of the beam from being fully guided as intended.

[0299] Like multi-segment angled Bessel beams, Airy laser beams can also benefit from phase-mask-based correction methods. These phase-mask-based correction methods can apply precise amounts of spherical aberration and compensate for off-axis aberrations from both the lens system and the light rays entering the glass interface at an angle.

[0300] Figure 40A This image illustrates an example segment 4000 with an outer rounded laser edge chamfer 4002, which can be formed by a multi-spot or multi-focus Gaussian beam (as described in the aforementioned publication "Protecting Edges: Ultrafast Laser-Modified C-Shaped Glass Edges") formed within segment 4000. Segment 4000 has a first surface 4004 and a second surface 4006 opposite to the first surface 4004. Segment 4000 defines a thickness T3, which is measured between surfaces 4004 and 4006. The thickness T3 is approximately 550 micrometers, but different thicknesses can be used in other embodiments. Diffractive optics can be used to form the multi-spot Gaussian beam, which can create an outer rounded shape for the edge chamfer 4002. The multi-spot Gaussian beam can achieve other complex edge shapes and arbitrary two-dimensional part shapes. However, crack control and separation at such high-angle edges can be challenging when using multi-spot Gaussian beams, compared to edges with perforations, where acid or hydroxide etching is typically required. Furthermore, the fabrication of optical components can be relatively complex when using multi-spot Gaussian beams.

[0301] Figure 40BThis image shows an example segment 4010 with an example C-shaped beveled edge made from a multi-spot Gaussian beam. Segment 4010 has a first surface 4018 and a second surface 4020 opposite to the first surface 4018. Segment 4010 defines a thickness T4, which is measured between surfaces 4018 and 4020. The thickness T4 is approximately 550 micrometers, but different thicknesses may be used in other embodiments. Diffractive optics can be used to form a multi-spot Gaussian beam to create a C-shaped beveled edge for edge chamfering. The C-shaped beveled edge typically comprises three surfaces, including surface 4012, surface 4014, and surface 4016.

[0302] To generate laser beams that produce C-shaped beveled edges and curved beveled edges, a programmable spatial light modulator (SLM) system can be used. A Gaussian beam emitted by a short-pulse laser is displayed on a phase mask shaped on the SLM, and the phase mask requires additional lenses to convert and reduce the laser beam into multiple angled Bessel beams or Airy beams within a specific sheet. The laser beam is characterized by imaging it with a camera (e.g., a charge-coupled device (CCD) camera or a complementary metal-oxide-semiconductor (CMOS) camera) and a microscope objective, scanning it through its focal point to observe the cross-sectional profile of the beam as the focal position changes.

[0303] For a laser beam configured to produce a C-shaped beveled edge, Figure 41A The image shows cross-sectional images produced by a laser beam used to cut a 0.7 mm thick sheet. Between each individual cross-sectional image, the focal position is adjusted by approximately 10 micrometers. Image sequence 4100 begins with the first image 4102 and progresses from left to right in the row to the left of line 4104, then moves to the next row to the left of line 4104. The sequence progresses from the last image to the left of line 4104 to the first image to the right of line 4104, and then the sequence progresses in a similar manner.

[0304] The peak grayscale intensity of the laser beam on the camera is based on Figure 41A Image calculations are performed, and the calculated peak grayscale intensity is used to obtain... Figure 41BFigure 4108 illustrates the variation of peak grayscale intensity with the focal position of the laser beam. Figure 4108 shows data points 4110 and a best-fit line 4112. The peak grayscale intensity remains at approximately 10 counts when the focal position is below 200 micrometers and above approximately 825 micrometers. However, the peak grayscale intensity rises to above 175 counts at focal positions between approximately 200 micrometers and approximately 825 micrometers. The maximum peak grayscale intensity of the best-fit line 4112 is approximately 165 counts when the focal position is approximately 500 micrometers. When the grayscale intensity is approximately 100 counts or more, the laser beam has sufficient intensity across a distance measured in air of approximately 550 micrometers to cut glass, corresponding to the beam's ability to cut glass approximately 700 micrometers thick.

[0305] When the focal position changes, the peak intensity position shifts laterally, and the peak intensity position also changes accordingly. Figure 41A Image computation. Figure 41C The results are shown in the figure, which is a graph showing the shift in peak position as the focus position changes. Figure 4114 shows data point 4116 corresponding to the peak x-coordinate and the best-fit line 4118 for the peak x-coordinate as the focus position changes. Figure 4114 also shows data point 4120 corresponding to the peak y-coordinate and the best-fit line 4122 for the peak y-coordinate as the focus position changes.

[0306] The best-fit line 4118 typically has three distinct linear segments. The first segment has a length A3 and a variation A5 at the focal position. The second segment has a length A6. This second segment typically remains at approximately the same peak position, so the length A6 corresponds to the variation at the focal position. The third segment has a length A4 and a variation A7 at the focal position. Both lengths A3 and A4 are approximately 209 micrometers. Both lengths A5 and A7 are approximately 200 micrometers. Furthermore, length A6 is approximately 180 micrometers. However, in other embodiments, these lengths A3-A7 may differ.

[0307] Additionally, for laser beams configured to produce curved, beveled edges, Figure 41D The image shows cross-sectional images produced by a laser beam used to cut a 1.1 mm thick sheet. Between each individual cross-sectional image, the focal position is adjusted by approximately 10 micrometers. Figure 41D Image sequence 4124 in the image sequence is similar to Figure 41A The sequence in the image 4126 begins, proceeds from left to right in the row to the left of line 4128, and then proceeds from left to right in the row to the right of line 4128.

[0308] The peak grayscale intensity of the laser beam is based on Figure 41D The image calculations in the image, and the calculated peak on-axis intensity, are used to obtain... Figure 41E Figure 4132 illustrates the variation of peak grayscale intensity with focal position. Figure 4132 shows data points 4134 of intensity on the peak axis and the corresponding best-fit line 4138. Peak grayscale intensity remains at approximately 10 counts when the focal position is below approximately 50 micrometers and above approximately 875 micrometers. However, peak grayscale intensity rises to higher levels at certain focal positions between approximately 50 micrometers and approximately 875 micrometers, with peak grayscale intensity reaching levels above 200 counts around a focal position of 350 micrometers. The maximum peak grayscale intensity of the best-fit line 4138 is approximately 190 counts when the focal position is approximately 400 micrometers. When the grayscale intensity is approximately 100 counts or more, the laser beam has sufficient intensity across a distance measured in air of approximately 750 micrometers to cut glass, corresponding to the beam's ability to cut glass approximately 1100 micrometers thick.

[0309] When the focal position changes, the peak intensity position shifts laterally, and the peak intensity position also changes accordingly. Figure 41D Image computation. Figure 41F The results are shown in Figure 4140, which illustrates the movement of the peak position in the x and y directions as the focal position changes in the z-direction. Figure 4140 shows data points 4142 corresponding to the peak x-coordinate at each focal position in the z-direction, the best-fit line 4144 associated with data point 4142, and data points 4146 corresponding to the peak y-coordinate at each focal position in the z-direction. Because the best-fit line associated with data point 4146 tracks it so closely, it is not easily observed.

[0310] Although Figure 41D-41F Results were shown using an Airy laser beam to cut 1.1 mm thick material, but the beam size can be scaled up or down to cut thicker or thinner materials, and when scaled up or down, the beam can have essentially the same cross-sectional profile and other properties.

[0311] Figure 42A The schematic diagram illustrates an example process flow for forming and cutting segments within a sheet. At stage 4200A, a segment 4206 is provided in the sheet, with a frame 4202 surrounding the segment 4206. The frame 4202 is typically 60 mm by 80 mm in size, and the segment 4206 is typically about 44 mm by 60 mm in size. However, in other embodiments, the frame 4202 and segment 4206 may have different dimensions. A perforated profile 4204 is formed within the sheet to separate the frame 4202 and segment 4206.

[0312] Between stage 4200A and stage 4200B, the sheet can be ion-exchanged. At stage 4200B, a release line 4208 can be formed in the frame 4202, allowing the frame 4202 to be easily separated from the segment 4206. At stage 4200C, the segment 4206 is released from the remainder of the frame 4202 by separating the frame 4202 at the release line 4208 and close to the perforated profile 4204. Once stage 4200 is complete, the segment 4206 is completely separated from the remaining frame 4202.

[0313] Once segment 4206 is separated, an edge strength test is performed on segment 4206, and Figure 42B These test results are shown in the document. Figure 42B Chart 4250 shows the edge strength of various example sheets formed in various ways. Sections with edges formed in three different ways were tested. Sections with straight, perforated edges were also tested. Figure 42B The first set of data points represents the segment with C-shaped beveled edges removed from the surrounding frame prior to ion exchange processing. Figure 42B The second set of data points is represented in the diagram. (Using...) Figure 42A The C-shaped beveled edge shown in the image (which was not removed from the surrounding frame before ion exchange processing) is made by... Figure 42B The third set of data points is represented in the diagram.

[0314] Graph 4250 shows when different segments fail based on the amount of stress applied to them. For example, at lower bending strength values ​​on the x-axis, each line has its lowest percentage of failure. However, as stress increases, and as progressing from left to right in Graph 4250, the percentage of failure shown on the y-axis increases. When a given line in Graph 4250 is steeper, the process for manufacturing the segment corresponding to that line is more consistent. When a given line in Graph 4250 is less steep, the process for manufacturing the segment corresponding to that line is less consistent because failure propagation is greater. Each line in the graph shows a roughly consistent slope, and the results indicate that the edge strength is nominally equal. This shows that the edge strength obtained when ion-exchange processing is performed after perforation is formed in the sheet but before the removable segment is removed is comparable to the edge strength obtained when ion-exchange processing is performed after the removable segment is removed. The tested segments were ion-exchanged in the same bath. The same test was performed on bent beveled edges, and these edges were relative to... Figure 42B The edges shown have similar edge strength results.

[0315] Since the compression layer formed by the material diffused during the ion exchange process is important for providing strength to the sheet and / or segments, scanning electron microscopy (SEM) images and elemental analysis by energy-dispersive X-ray spectroscopy (EDS) can be used to determine whether the ion-exchange material has completely penetrated the perforations. The results indicate that the DOL of the compression zone located along the direct perforations is indeed very uniform. To understand whether this also applies to nonlinear laser-cut edges, similar tests were performed on C-shaped and curved beveled edges. The test samples were ion-exchanged in a potassium nitrate (KNO3) bath at approximately 440 degrees Celsius for about 3 hours.

[0316] Figure 43 The results are shown in the figure, which displays various scanning electron micrographs of the material diffused by ion exchange. Figure 43 Three samples are shown, including sample 4316, sample 4330, and sample 4344.

[0317] Figure 43 The DOL of the compressed zone in other embodiments described herein can be measured by determining the extent to which the ion exchange material diffuses into the underlying sheet or segment until the ion exchange material reaches background levels in the sheet or segment, and the DOL can be measured using SEM equipment or other imaging equipment. The DOL can be measured using electron probe microanalysis (EPMA) or other mass spectrometry methods. When an increase in the level of ion exchange material (e.g., potassium ions, sodium ions, etc.) relative to the level of ion exchange material in the unexchanged sheet or segment may not be detectable, the ion exchange material reaches background levels.

[0318] In the first sample 4316, the thickness of the section shown is approximately 0.55 mm, and the shape and size of the section are similar to... Figure 42A Segment 4206 is similar. The segment shown has: a first surface 4318 having a compression region 4324 located at the first surface 4318; a second surface 4322 opposite to the first surface 4318 having a compression region 4328 located at the second surface 4322; and an edge surface 4320 extending between the first surface 4318 and the second surface 4322, the edge surface having a compression region 4326 located at the edge surface 4320. The edge surface 4320 is formed using an Airy beam. As shown, the DOL at each surface in the surface is generally kept uniform, even at the corners where each surface in the surface intersects. The DOL at all surfaces is approximately 40 micrometers.

[0319] In the second sample 4330, the thickness of the segment shown is approximately 0.55 mm, and the shape and size of the segment are similar to... Figure 42A Section 4206 is similar. The second sample 4330 is a control sample. The section used in the second sample 4330 was cut with an Airy beam but removed from the remainder of the sheet before ion exchange. The section shown in the second sample 4330 has: a first surface 4332 having a compression zone 4338 positioned thereon; a second surface 4336 opposite to the first surface 4332 having a compression zone 4342 positioned thereon; and an edge surface 4334 extending between the first surface 4332 and the second surface 4336, the edge surface having a compression zone 4340 positioned thereon. The edge surface 4334 was formed with an Airy laser beam. As shown, the DOL at each surface in the surface is generally kept uniform, even at the corners where each surface intersects. The DOL is approximately 40 micrometers. The image of the second sample 4330 shows that the compression zone not only completely covers both the top and bottom surfaces but also covers the entire laser-formed glass edge. However, in the small spalling area near the corner between edge surface 4334 and first surface 4332, the reduced amount of ion exchange material in the compressed area results in a smaller DOL. This spalling area is an artifact of the sample preparation process before SEM and is not present during laser perforation or ion exchange processes.

[0320] In the third sample 4344, the thickness of the segment shown is approximately 0.7 mm, and the shape and size of the segment are similar to... Figure 42A Similar to segment 4206. The segment shown has: a first surface 4346 having a compression zone 4352 located at the first surface 4346; a second surface 4350 opposite to the first surface 4346, having a compression zone 4356 located at the second surface 4350; and an edge surface 4348 extending between the first surface 4346 and the second surface 4350, the edge surface having a compression zone 4354 located at the edge surface 4348. The edge surface 4348 is formed with a C-shaped beveled edge. As shown, the DOL at each surface in the surface is generally kept uniform, even at the corners where each surface in the surface intersects. The DOL is approximately 40 micrometers.

[0321] For the first sample 4316 and the third sample 4344, the ion-exchange material forming the compression zone has been uniformly penetrated around the laser-formed perforations and edges. Although the ion-exchange material is not uniformly distributed in the third sample 4330, this is due to the pre-SEM sample preparation process as described above, and this exfoliation zone was not present during the laser perforation or ion-exchange process. Therefore, the ion-exchange process can be effectively performed on the sheet before separating the segments from the sheet, regardless of whether the edges are C-shaped or curved. However, even when using other chamfering methods (such as chamfers formed by multi-spot or multi-focus Gaussian beams), performing the ion-exchange process on the sheet may be effective.

[0322] A ball-on-ring test can be performed to evaluate the maximum force applied to a laser-perforated section contained in the sheet, and the maximum deflection of the laser-perforated section in the sheet before the section is released from the sheet. Figure 44 The top-view diagram shows the sheet material that can be used for ball testing on this ring, and Figure 45 The image shows a side view of the ball-on-ring test assembly.

[0323] Sheet 4400 includes an inner segment 4404 having a circular shape. Sheet 4400 also includes a frame 4402 positioned outwardly from the inner segment 4404, and perforations 4406 can be formed at a location between the inner segment 4404 and the frame 4402. These perforations 4406 can extend from one surface of sheet 4400 to the opposite surface of sheet 4400. The inner segment 4404 includes a diameter A8. Sheet 4400 also has a rectangular shape, wherein sheet 4400 has a length A9 and a width A10, and sheet 4400 also has a relatively constant thickness A11, such as... Figure 45 As shown in the diagram. Adjusting the diameter A8, length A9, width A10, and thickness A11 can adjust the maximum force and maximum deflection during the ball test on the ring. In some embodiments, the length A9 and width A10 can be approximately 160 mm, but other values ​​can be used for the length A9 and width A10.

[0324] exist Figure 45 In this context, the perforation 4406 extends along a line perpendicular to the opposite surface of the sheet 4400. However, as described herein, the perforation 4406 may have other non-linear shapes, or the perforation 4406 may be aligned in different ways.

[0325] The ball-on-ring test assembly also includes a load ring 4408 and a contact ball 4410. The load ring 4408 is positioned such that it contacts the frame 4402 at a location radially outward from the inner segment 4404, where the load ring 4408 statically supports the frame 4402. The contact ball 4410 is positioned such that it contacts the inner segment 4404 near its center. The contact ball 4410 applies a force to the inner segment 4404, as indicated by arrow D4. When this force is applied, the load ring 4408 provides a force opposite to the force induced at the contact ball 4410 and deflects within the sheet 4400, as indicated by arrow D3. Specifically, a greater level of deflection occurs at the inner segment 4404 compared to the frame 4402. During the ball-on-ring test, the observed sheet deflection may continue to increase as the force applied to the contact ball 4410 increases. As the applied force increases, the sheet deflection may continue to increase until the inner segment 4404 is suddenly released relative to the frame 4402, at which point the maximum applied force and maximum deflection can be recorded. The amount of force applied to the contact ball 4410 can be measured using a load cell. Alternatively, various types of measuring devices can be used to measure the deflection of the sheet and / or the inner segment 4404, allowing the deflection to be determined as a function of the amount of applied force. The ring-ball testing method described herein generates a rotationally symmetric stress field that can be easily modeled.

[0326] A ring ball test was performed on sheets with different properties to evaluate the maximum deflection and maximum force required to release laser-perforated sections from the sheets. In the initial test, a profile with perforations at right-angled edges was created using a laser, and... Figure 46 The chart shows the test results. This test evaluated three different sheet thicknesses. The first sheet was 0.7 mm thick, the second was 1.1 mm thick, and the third was 1.3 mm thick. Additionally, segments provided in the glass sheet were arranged in circular shapes with different diameters to evaluate the effect of segment size. The tested diameters included 40 mm, 60 mm, 80 mm, 100 mm, and 120 mm. Furthermore, the sheets contained glass material.

[0327] exist Figure 46 In the charts, peak load is included as a variable on the Y-axis, where peak load is in Newtons. Additionally, segment diameter is included as a variable on the X-axis, where perforation diameter is in millimeters. Data point 4602 corresponds to a test performed on a sheet with a thickness of 1.3 mm, data point 4604 corresponds to a test performed on a sheet with a thickness of 1.1 mm, and data point 4606 corresponds to a test performed on a sheet with a thickness of 0.7 mm.

[0328] like Figure 46As shown in the chart, smaller diameter segments require greater force to separate from the sheet. The far left of the chart shows segments with a minimum diameter of approximately 40 mm, and these segments have the highest peak load relative to other diameter sizes, all other things being equal. The far right of the chart shows segments with a maximum diameter of approximately 120 mm, and these segments have the lowest peak load relative to other diameter sizes, all other things being equal. The smaller the diameter, the higher the peak load because smaller segments are physically stiffer than larger segments, and therefore require more force to deflect the segment sufficiently to pull the edges inward and create enough clearance for the segment to release.

[0329] Furthermore, when using thicker sheets, releasing the laser-perforated sections requires greater force. Data points 4602 (each located near the top of chart 4600) correspond to a sheet thickness of 1.3 mm, the highest thickness among the data points presented in chart 4600. Data point 4602 has the highest peak load compared to the other data points presented in chart 4600. Data point 4606 (each located near the bottom of chart 4600) corresponds to a sheet thickness of 0.7 mm, the lowest thickness among the data points presented in chart 4600. Data point 4606 has the lowest peak load compared to the other data points presented in chart 4600. Thicker sheets are generally stiffer, which may explain the increased force required with increasing sheet thickness. As the thickness is adjusted, the measured peak load typically increases with the cube of the thickness (t). 3 The increase is related to the mechanical beam theory.

[0330] Tests were also conducted to evaluate the effects of using a laser to generate nonlinear perforations compared to using basic linear perforations. Figure 47 Graph 4700 illustrates the peak load as a function of segment diameter when using two different chamfering methods. In Graph 4700, data were obtained using glass slides approximately 0.7 mm thick, and the segment diameters used on the glass slides varied. The x-axis of the graph shows the different test conditions for different data points. Data point 4702 used a basic straight perforation and a segment with a diameter of 40 mm. Data point 4704 used a non-linear perforation to produce a C-shaped beveled edge and a segment with a diameter of 42 mm. Data point 4706 used a basic straight perforation and a segment with a diameter of 80 mm. Data point 4708 used a laser-formed perforation to produce a C-shaped beveled edge and a segment with a diameter of 82 mm. The laser-formed perforations used for data points 4704 and 4708 produced C-shaped beveled edges similar to those described in other embodiments herein.

[0331] Although data points 4702 and 4704 were obtained using similar segment diameters of 40 mm and 42 mm, respectively, the average peak load of data point 4704 is approximately 53.8446 Newtons, while the peak load of data point 4702 is approximately 19.1813 Newtons. Therefore, the peak load of data point 4704 is approximately 2.8 times that of data point 4702. Data point 4702 comprises four data points with peak loads of 19.304 Newtons, 19.016 Newtons, 19.151 Newtons, and 19.254 Newtons. Data point 4704 comprises five data points with peak loads of 56.782 Newtons, 54.931 Newtons, 55.481 Newtons, 51.858 Newtons, and 50.171 Newtons. If all other variables remain constant, then the larger diameter used to obtain data point 4704 relative to data point 4702 will result in a reduction in peak load.

[0332] Although data points 4706 and 4708 were obtained using similar segment diameters of 80 mm and 82 mm, respectively, the peak load of data point 4708 is approximately 32.1938 N, while the peak load of data point 4706 is approximately 10.1484 N. Therefore, the peak load of data point 4708 is approximately 3.2 times that of data point 4706. Data point 4706 comprises five data points with peak loads of 10.144 N, 10.338 N, 10.683 N, 9.647 N, and 9.93 N. Data point 4708 comprises six data points with peak loads of 32.214 N, 32.842 N, 33.239 N, 31.575 N, 30.323 N, and 32.97 N. If all other variables remain constant, the larger diameter used to obtain data point 4708 relative to data point 4706 would result in a decrease in peak load. Therefore, the C-shaped beveled edge significantly increases the peak load required for release of the laser-perforated segment compared to a straight, perforated edge, indicating that the nonlinear perforation formed by the laser improves the robustness of the ejection shield.

[0333] Use Airy laser beams to create additional laser chamfers, and Figure 48 The peak load of the sheet perforated using an Airy laser beam is shown relative to other test sheets perforated using direct beam perforation. In Figure 4800, the thickness for all data points is 0.7 mm. Additionally, test results for different perforation types are also shown.

[0334] Data point 4802 corresponds to a sheet with a curved beveled edge having a segment diameter of approximately 40 mm, and the average peak load of data point 4802 is approximately 41.6633 Newtons. Data point 4804 corresponds to a sheet with a straight perforation having a segment diameter of approximately 40 mm, and the average peak load of data point 4804 is approximately 19.1813 Newtons. Data point 4806 corresponds to a sheet with a C-shaped beveled edge having a segment diameter of approximately 42 mm, and the average peak load of data point 4806 is approximately 53.8446 Newtons. Therefore, the peak load of data point 4802 using the curved beveled edge is approximately 2.17 times that of data point 4804 using the straight perforation, and the peak load of data point 4806 using the C-shaped beveled edge is approximately 2.81 times that of data point 4804 using the straight perforation. The peak load at data point 4806 using a C-shaped bevel edge is approximately 1.29 times that of data point 4802 using a curved bevel edge. Therefore, compared to using a straight-through perforation, curved and C-shaped bevel edges significantly reduce the likelihood of segmental release, and the C-shaped bevel edge requires approximately 29% more force before segmental release occurs compared to the curved bevel edge. While the results for curved and C-shaped bevel edges differ, these differences are likely due to slight differences in the total vertex amplitude of the specific curved and C-shaped bevel chamfers tested, and these chamfers would likely have similar peak load values ​​if the total vertex amplitude were the same. Generally, chamfers with larger vertex amplitudes or deeper bevels are expected to require the greatest force to produce sufficient deflection and clearance for ejection.

[0335] Data point 4808 corresponds to a sheet with a curved, beveled edge having a section diameter of approximately 80 mm, and the average peak load of data point 4808 is approximately 26.695 Newtons. Data point 4810 corresponds to a sheet with a straight perforation having a section diameter of approximately 80 mm, and the average peak load of data point 4810 is approximately 10.1484 Newtons. Data point 4812 corresponds to a sheet with a C-shaped beveled edge having a section diameter of approximately 82 mm, and the average peak load of data point 4802 is approximately 32.1938 Newtons.

[0336] Therefore, the peak load of data point 4808 using the curved beveled edge is approximately 2.63 times that of data point 4810 using the straight-through perforation, and the peak load of data point 4812 using the C-shaped beveled edge is approximately 3.17 times that of data point 4810 using the straight-through perforation. The peak load of data point 4812 using the C-shaped beveled edge is approximately 1.21 times that of data point 4808 using the curved beveled edge. Therefore, compared to using the straight-through perforation, the curved beveled edge and the C-shaped beveled edge significantly reduce the likelihood of segmental release, and the C-shaped beveled edge requires approximately 21% more force before segmental release occurs compared to the curved beveled edge. Although the results for the curved beveled edge and the C-shaped beveled edge differ, these differences are likely due to slight differences in the total vertex amplitude of the specific curved beveled edge and the C-shaped beveled edge tested, and these bevels would likely have similar peak load values ​​if the total vertex amplitude of these bevels were the same.

[0337] Multispot Gaussian beams can also be used. Based on the larger vertex height chamfers that can be produced using multispot Gaussian beams, these beams are expected to exhibit even greater pop-out robustness than C-shaped and curved beveled edges. Finite element modeling confirms this general expectation and reveals that pop-out decreases as the larger chamfer vertex distance increases, and when other factors such as profile geometry and load conditions remain otherwise constant.

[0338] Additionally, polishing (e.g., brush polishing) is typically performed after ion exchange processing of sheets or segments, and pre-beveling the edges of segments before ion exchange can be beneficial for various reasons. In the case of brush polishing segments with right-angled edges that have already undergone ion exchange, the range of the final edge profile obtainable is limited. While brush polishing itself can be used to produce a wide range of edge profiles, if it is used to remove significant amounts of material at corners, it may completely remove the compression zones at those corners. By performing laser beveling before ion exchange, the ion-exchanged material can be retained at a more consistent level around the surface of the segment, even after any polishing. Figures 49A-49D This is demonstrated in the document.

[0339] Figure 49AAn example segment 4900A with compression zones is shown, wherein the compression zones contain ion-exchange material diffused at the surface of the segment, and wherein segment 4900A is not pre-beveled prior to the ion-exchange process. Segment 4900A has a first surface 4902A, a second surface 4902C opposite to the first surface 4902A, and an edge surface 4902B extending between the first surface 4902A and the second surface 4902C. Compression zones are located at each of the surfaces 4902A-4902C. For example, compression zone 4904A is located at the first surface 4902A, compression zone 4904E is located at the second surface 4902C, and compression zone 4904C is located at the edge surface 4902B. Additionally, compression region 4904B is located at the corner where the first surface 4902A and the edge surface 4902B intersect, and compression region 4904D is located at the corner where the second surface 4902C and the edge surface 4902B intersect. The compression regions typically have a DOL T5 at all surfaces and corners of segment 4900A, with the DOL T5 at surfaces 4902A-4902C being approximately the same. However, due to the presence of multiple surfaces where ion exchange diffusion may occur, the DOL T5 of compression regions 4904B and 4904D at the corners is slightly larger.

[0340] However, during polishing, diffused ion-exchange material may be removed at different locations on the sheet. Polishing can be performed using brush polishing techniques, which can remove edges to remove very small amounts of material (e.g., about 10 micrometers) from the surface. However, brush polishing can also be used to remove more material from the surface. Brush polishing can perform fine polishing without completely removing compressed areas at the edge surfaces, resulting in segments with high edge strength due to the removal or reduction of the size of any edge defects. Additionally, in the case of brush polishing, the roughness of the brush-polished surface may be lower than that of other unbrushed surfaces. For example, the average surface roughness of the brush-polished surface may be 100 nanometers or less.

[0341] Figure 49B Section 4900B is shown, which illustrates section 4900A after polishing. Line 4906 shows an example edge profile after polishing. As shown, the compression zones 4904B and 4904D at the corners are removed after polishing, along with some of the compression zones 4904A, 4904C, and 4904D on other surfaces. Therefore, after polishing, compression zones are not present on all surfaces of the section, and they exist at inconsistent levels around the surface.

[0342] To avoid locations lacking compression zones, brush polishing can be performed in different ways to obtain different edge profiles, where less material is removed at the corners. Because of the compression zones at the edges, this can provide higher edge strength to the segment. However, by removing less material at the corners, the final edge profile achievable is more limited—the contact angle achievable at the edge surface becomes more limited, and the vertex distance of the edge also becomes more limited.

[0343] However, with the edges of the section pre-cut, the compression zone can be kept at a more consistent level across all surfaces of the section. Figure 49C An example segment has been pre-beveled and then exposed to an ion-exchange material. Segment 4900C has a first surface 4912A, a second surface 4912E opposite to the first surface 4912A, and an edge surface extending between the first surface 4912A and the second surface 4912E. The edge surface comprises a first portion 4912B, a second portion 4912D, and a vertex portion 4912C. The vertex portion 4912C is relatively flat, while the first portion 4912B and the second portion 4912D are rounded and connect the edge surface to the first surface 4912A and the second surface 4912E.

[0344] Compression zones containing ion exchange material are located at each surface in the surface. For example, compression zone 4914A is located at the first surface 4912A, compression zone 4914B is located at the first portion 4912B of the edge surface, compression zone 4914C is located at the vertex portion 4912C of the edge surface, compression zone 4914D is located at the second portion 4912D of the edge surface, and compression zone 4914E is located at the second surface 4912E. The compression zones typically have a DOL T6 at all surfaces of segment 4900C, where this DOL T6 is substantially the same at surfaces 4912A-4912E.

[0345] Figure 49D This is a schematic diagram showing section 4900D, where section 4900D is shown after polishing. Figure 49CSection 4900C. Even after polishing, the compression zone remains at all surfaces. Line 4918 indicates the amount of material removed at the edge surface of section 4900D. As shown, some portions of compression zones 4914B, 4914C, and 4914D are removed at the edge surfaces, resulting in smaller DOLs (Density of Lithometry) for compression zones 4914B, 4914C, and 4914D at the edge surfaces compared to compression zones 4914A and 4914E at other surfaces. However, the DOL at the edge surfaces can still remain greater than about 3 micrometers at all locations on the edge surfaces. Retaining the DOL ensures that the compression zone is preserved at the edge surfaces, thereby improving edge strength. In some embodiments, the DOL of compression zones 4914A and 4914E at surfaces 4912A and 4912E can be at least about 5 micrometers larger than the DOL of compression zones 4914B, 4914C, and 4914E at the edge surfaces. Polishing may also lead to a decrease in the surface concentration of ion exchange material (e.g., potassium) at the edge surfaces, relative to the surface concentration of ion exchange material at surfaces 4912A and 4912E.

[0346] By beveling the edges prior to ion exchange processing, the final vertex distance of the edge surfaces can be greater than or equal to the DOL of the compression zones at surfaces 4912A and 4912E. Since compression zones exist at all surfaces, and therefore compressive stress is generated at all surfaces, the sheet maintains high strength while also providing a large contact angle at the edge surfaces, making the corners of the beveled parts less likely to fail due to cracking or chipping.

[0347] Figure 50 This is a block diagram of various components within an example laser system 5000. Laser system 5000 includes a laser 5002. Laser 5002 can have various forms, and in some embodiments, the laser can be configured to generate a laser beam in the form of pulse bursts. In some embodiments, the laser can be an ultrafast laser configured to generate a laser beam in pulses with pulse widths on the order of femtoseconds or picoseconds. Laser 5002 may have properties similar to those of other lasers used herein, but in other embodiments, these properties may be modified.

[0348] The laser system 5000 also includes a motion platform 5008, a rotatable optical element holder 5010, and one or more actuators 5014. The motion platform 5008 can serve as a mechanical stage on which a sheet can be positioned during laser processing. The motion platform 5008 can be configured to hold the sheet in a fixed position relative to the motion platform 5008, and the motion platform 5008 can be configured to move as needed to form perforations or modifications at appropriate locations within the sheet. Actuators 5014 can facilitate movement of the motion platform 5008, but in other embodiments, actuators may be included within the motion platform 5008 to generate movement of the motion platform 5008. The rotatable optical element holder 5010 can be configured to hold a rotatable optical element when it is used. The rotatable optical element holder 5010 can be configured to hold the rotatable optical element in a fixed position relative to the rotatable optical element holder 5010, and the rotatable optical element holder 5010 can be configured to move and / or rotate as needed to position the rotatable optical element in the correct location and / or orient it correctly. An actuator 5014 can facilitate movement of the rotatable optical element holder 5010, but in other embodiments, an actuator may be included in the rotatable optical element holder 5010 to produce movement of the rotatable optical element holder 5010. The actuator 5014 can be provided in various forms. The actuator 5014 can be provided as a linear actuator, a rotary actuator, a mechanical actuator (such as a rack and pinion or cam actuator), or other types of actuators.

[0349] The laser system 5000 also includes a spatial light modulator 5012. The spatial light modulator 5012 is a device that can apply a phase (in 256 steps) between 0 and 2π to an incident laser beam reflected by the spatial light modulator 5012 at each individual pixel. The spatial light modulator 5012 may have a specific resolution (e.g., 1152 pixels by 1920 pixels) and a certain spacing (e.g., approximately 8 micrometers) between adjacent pixels. However, the spatial light modulator 5012 may have different resolutions, spacings, and other properties. In some embodiments, the spatial light modulator 5012 may be a liquid crystal spatial light modulator configured to use liquid crystal to modulate light. In other embodiments, the spatial light modulator 5012 may be a digital micromirror device (DMD) configured to use an array of small mirrors to reflect and modulate light. However, other types of modulators may also be used. Furthermore, passive beamforming devices such as diffractive optical elements may also be used.

[0350] The laser system 5000 also includes one or more processors 5004. Processor 5004 can be configured to perform various functions, and processor 5004 can execute operations or instructions stored in memory device 5006 or other locations. Processor 5004 can be any means configured to execute various programmed operations or instructions stored in memory device (e.g., memory device 5006), such as means or circuit systems operating according to software, or means or circuit systems otherwise embodied in hardware or a combination of hardware and software (e.g., a processor operating under software control, or a processor embodied as an application-specific integrated circuit (ASIC) or field-programmable gate array (FPGA) specifically configured to perform the operations described herein, or a combination thereof), thereby configuring means or circuit systems to perform the corresponding functions of processor 5004 as described herein.

[0351] The laser system 5000 also includes a memory device 5006. In one example embodiment, the memory device 5006 may include one or more non-transitory storage devices or memory devices, such as fixed or removable volatile and / or non-volatile memory. The memory device 5006 may be configured to store instructions, computer program code, and additional data in a non-transitory computer-readable medium for use, such as by the processor 5004, thereby enabling components of the laser system 5000 to perform various functions according to an example embodiment of the invention. For example, the memory device 5006 may be configured to buffer input data for processing by the processor 5004. Additionally or alternatively, the memory device 5006 may be configured to store instructions for execution by the processor 5004. The memory device 5006 may include computer program code configured to cause the processor 5004 to perform the various methods described herein when executed. The memory device 5006 may serve as a non-transitory computer-readable medium on which software instructions are stored, which, when executed by one or more processors, cause the methods described herein to be performed.

[0352] The laser system 5000 may also include one or more communication interfaces 5016. The communication interface 5016 may be configured to communicate with other components external to the laser system 5000. However, the communication interface 5016 may also be configured to enable communication between components within the laser system 5000. The communication interface 5016 may also include one or more communication modules configured to communicate with each other in various ways, including, for example, via a network. In this regard, the communication interface 5016 may include any of a variety of different communication backbones or frameworks, including, for example, Ethernet, Global Positioning System (GPS), cellular, Wi-Fi, or other suitable networks. The network may also support other data sources, including GPS. In this regard, the laser system 5000 may also include many other peripheral devices. In some embodiments, some or all of the communication interfaces in the communication interface 5016 may be configured to communicate using short-range wireless technologies, such as Bluetooth (e.g., Bluetooth version 4.1 or another version), Wi-Fi, NearLink, Near Field Communication (NFC), Low Power Wide Area Network (LPWAN), Ultra Wide Area Network (UWB), Wireless Local Area Network (WLAN) compliant with IEEE 802.11(b), IEEE 802.11(g) and / or IEEE 802.11(n) standards and / or Low Rate Wireless Personal Access Network (LR-WPAN) compliant with IEEE 802.15.4 standards.

[0353] The components of the laser system 5000 can be connected in various ways, and in some embodiments, the connection between components can be wired or wireless. For example, the laser system 5000 can use Bluetooth, Wi-Fi, or other similar short-range wireless technologies to connect to other devices. However, other connection methods can be used for the laser system 5000.

[0354] Figure 51 This is a flowchart illustrating an example method 5100 for modifying a sheet to form internal features within the sheet. At operation 5102, a laser beam is generated. In some embodiments, this laser beam may be an Airy beam, a caustic beam, a Bessel beam, a multi-segment Bessel beam, or a multi-spot or multi-focus Gaussian beam, but in other embodiments, other laser beams may also be generated.

[0355] At operation 5104, the laser beam is guided to the rotatable optical element. In some embodiments, the rotatable optical element may be similar to... Figure 18AAlternatively, it can be one of the rotatable optical elements in 18B. The rotatable optical element may be provided in the form of a Duff prism and may include a first surface and a second surface. A laser beam can be directed to the rotatable optical element such that the laser beam is received at the first surface with a first beam profile, exits the rotatable optical element at the second surface with a second beam profile, and is guided to the sheet after exiting the first optical element to create an internal feature in the sheet. However, the rotatable optical element may include a k-mirror assembly.

[0356] At operation 5106, a rotatable optical element is rotated. The rotatable optical element can rotate by a first angle, and it can rotate when the laser beam is actively guided to it. By doing so, internal features can be formed in the sheet. When the first optical element rotates by the first angle, the second beam profile rotates by a second angle relative to the first beam profile. The second angle can be at least about 1.25 times the first angle, at least about 1.5 times the first angle, at least about 1.75 times the first angle, at least about 2 times the first angle, at least about 2.25 times the first angle, or at least about 2.5 times the first angle.

[0357] At operation 5108, it is determined whether additional internal features are needed. If no additional internal features are needed, then method 5100 can be completed. If additional internal features are needed, then method 5100 can proceed to operation 5110. At operation 5110, the position of the sheet relative to the rotatable optical element can be adjusted, and then method 5100 can be performed again by the operations discussed. By adjusting the position of the sheet, any new internal features formed on the sheet can be formed at different locations. Although method 5100 is used to form internal features in the sheet, method 5100 can also be used to make other modifications to the sheet.

[0358] Figure 52 This is a flowchart illustrating an example method 5200 for slicing segments of a sheet to form individual substrates. In method 5200, the sheet and the segments therein may contain glass, and the sheet may undergo ion exchange to increase the strength of the sheet and the segments therein.

[0359] At operation 5202, laser perforation is formed in the sheet. The segment profile within the glass sheet is defined by the laser perforation process. Laser perforation can be performed in a pattern to form the segment profile, wherein the segment has one or more internal edges. Laser perforation can be formed using a laser beam (such as a multi-segment Bezier laser beam, a continuously curved Airy laser beam, or a multi-spot Gaussian beam).

[0360] In some embodiments, any segment within the sheet may be related to the reference. Figure 32 The described segments are similar. A segment may include a first surface extending in a first plane and a second surface opposite to the first surface, wherein the second surface extends in a second plane parallel to the first plane. An edge surface may extend between the first and second surfaces, and the edge surface may have a non-linear profile with vertices. A first corner may connect the edge surface and the first surface, and a second corner may connect the edge surface and the second surface. The edge surface may extend further at its vertices compared to at the first and second corners. The sheet and any segments formed therein may contain glass or other materials. Any laser perforations formed may penetrate the entire depth of the sheet.

[0361] At operation 5204, the sheet undergoes ion exchange processing. Ion exchange processing can be performed before any segments have been cut from the sheet. The perforations formed in operation 5202 can serve as ion exchange channels, and the internal edges of segments within the sheet can be fully ion exchanged, even if the segments are held within a larger sheet by the ion exchange process. By using laser perforation processes that can produce non-linear shapes (e.g., bending perforations, multi-segment perforations, etc.), edge chamfering can more effectively hold segments within a larger sheet. This solves the problem of segments "popping out" during subsequent processing. The material diffused during ion exchange can be positioned along the first surface, the second surface, and the edge surfaces of the segments formed within the sheet.

[0362] Laser perforation itself includes a modified area that penetrates the depth of the sheet. This laser-modified area forms a beveled internal part edge; for example, the laser perforation and the edge formed by it can be curved, and / or may contain multiple angles penetrating the depth of the sheet. Therefore, laser perforations can have more complex shapes than other laser perforations, which are typically straight.

[0363] Laser perforation can create perforations within a sheet, and these perforations can have any shape described herein. For example, perforations can have... Figure 26A Or any shape shown in 26B. As described herein, perforation can make the segment have a contact angle between a line perpendicular to its flat side surface and the edge surface, and these contact angles can be at least about 10 degrees, at least about 12.5 degrees, at least about 15 degrees, at least about 17.5 degrees, or at least about 20 degrees. These contact angles can be measured at the corner where the edge surface intersects the flat side surface. Laser perforation can be formed using multiple angled Bessel beam profiles, caustic beam profiles, modified Airy beam profiles, or curved Bessel beam profiles, but other laser beam profiles may also be used in other embodiments.

[0364] At operation 5206, a coating material may be applied to the sheet or a segment therein. The coating material may be an ink, a dielectric coating (such as an anti-reflective layer), a metal, or a polymer. However, other coating materials may be used. The coating material may be selected to impose different properties on the sheet and the segments therein. For example, the coating material may be used to alter the decorative appearance of the sheet, reduce the reflectivity of the material, or apply other properties. In some embodiments, operation 5206 may optionally be omitted.

[0365] At operation 5208, a section can be released from other parts of the sheet. The frame of the glass sheet is cut off, and this may allow the part to be released from the part whose profile was defined during the laser perforation step.

[0366] At operation 5210, the edge surfaces of the segment may be polished. Polishing may be optionally performed to further enhance the edge strength of the segment. Polishing may be performed using a fine polishing process (such as brush polishing) or other methods. Even when polishing is performed at operation 5210, the DOL of the material that can be removed by polishing may be less than the DOL of the ion exchange material diffused during operation 5204. In other words, even after operation 5210, the compression zone containing the ion exchange material may remain positioned around the edge surface and the other surfaces of the segment. However, polishing at the edge surface may tend to reduce the DOL of the compression zone at the edge surface relative to the other surfaces of the segment. In some embodiments, the DOL of the compression zone at the edge surface may be at least about 5 micrometers smaller than the DOL of the compression zone at each of the first and second surfaces.

[0367] Figure 53 This is a flowchart illustrating an example method 5300 for forming a beveled edge in a sheet. In some embodiments, the sheet may contain glass.

[0368] At operation 5302, a laser beam is generated. The laser beam may be a caustic laser beam or a bent Bezier laser beam. In some embodiments, the laser beam may have an intensity profile, and the intensity profile may have a rectangular or elliptical shape. However, in other embodiments, the intensity profile may also use other shapes. In some embodiments, the laser beam may be generated in bursts, wherein each burst contains multiple pulses. Each burst may include at least five pulses, and a time delay may be provided between each pulse. In some embodiments, the time delay may be at least about 12 nanoseconds, but different time delay values ​​may be used in other embodiments. At operation 5304, the laser beam is directed onto the sheet such that the laser beam can form a beveled edge.

[0369] At operation 5306, a first phase is applied to the laser beam. The first phase may be a prism phase. Compared to when no first phase is applied, the first phase can reduce the angle of the light rays within the laser beam relative to the optical axis. Alternatively, compared to when no first phase is applied, the first phase can reduce the resolution requirement of the phase mask. In some embodiments, operation 5306 can only be performed if the laser beam generated at operation 5304 is a caustic beam.

[0370] At operation 5308, a second phase is applied to the laser beam. Compared to when no second phase is applied, the second phase can flatten the intensity profile of the laser beam in its longitudinal direction (e.g., in the z-coordinate). Additionally or alternatively, compared to when no second phase is applied, the second phase can increase the usable length of the laser beam during cutting. In some embodiments, operation 5308 can only be performed if the laser beam generated at operation 5304 is a caustic beam.

[0371] At operation 5310, using a binary phase mask, a first half of the laser beam can be formed downstream of and near the conjugate plane of the 4f system, and a second half can be formed upstream of and near the conjugate plane of the 4f system. In doing so, the binary phase mask can form the first half of the laser beam, which is symmetrical to the second half of the laser beam. In some embodiments, operation 5310 can only be performed when the laser beam is a curved Bessel laser beam.

[0372] At operation 5312, an optical delay element (e.g., a glass block) is positioned relative to the laser beam. The optical delay element can be positioned such that approximately half of the laser beam passes through it, while the remainder of the curved Bessel beam does not. By doing so, the optical delay element can offset half of the laser beam relative to the remainder of the laser beam along the length of the beam. In some embodiments, operation 5312 is performed only if the laser beam is a curved Bessel laser beam.

[0373] At operation 5314, a first polarization mask is positioned relative to the laser beam. In some embodiments, the first polarization mask may be a segmented quarter-wave plate. A segmented quarter-wave plate can be formed by obtaining a quarter-wave plate with four corner segments and flipping two opposing corner segments relative to each other. This can produce a multi-segment waveplate, wherein each waveplate segment has a fast axis orthogonal to the fast axis of its neighbor. In some embodiments, operation 5314 is performed only when the laser beam is a curved Bessel laser beam.

[0374] At operation 5316, a second polarization mask is positioned relative to the laser beam. In some embodiments, the second polarization mask may be a quarter-wave plate. By positioning the second polarization mask, circular input polarization can be obtained. In some embodiments, operation 5316 can only be performed if the laser beam is a curved Bessel laser beam.

[0375] Using method 5300, one or more beveled edges having desired characteristics can be formed, wherein the beveled edges have corresponding edge surfaces. The edge surfaces may extend between a first surface of the sheet and a second surface of the sheet opposite to the first surface. A contact angle is defined between a line perpendicular to the first surface and a portion of the edge surface immediately adjacent to the first surface, and the contact angle may be at least about 12.5 degrees or greater, at least about 15 degrees or greater, at least about 17.5 degrees or greater, at least about 20 degrees or greater, at least about 22.5 degrees or greater, at least about 25 degrees or greater, at least about 27.5 degrees or greater, or at least about 30 degrees or greater.

[0376] The methods described herein are merely exemplary and can be modified in various ways without departing from the scope of the invention. For example, various methods described herein can be modified to add additional operations or omit certain operations. In some embodiments, the methods described herein can be combined in whole or in part. In some embodiments, the order of operations in the methods can be adjusted, and in some embodiments, some operations can be performed simultaneously (e.g., in some embodiments, operations 5306 and 5308 can be performed simultaneously).

[0377] in conclusion

[0378] Benefiting from the teachings presented in the foregoing description and associated drawings, those skilled in the art will conceive of many modifications and other embodiments described herein. Therefore, it should be understood that the embodiments are not limited to the specific embodiments disclosed, and modifications and other embodiments are intended to be included within the scope of the invention. Furthermore, although the foregoing description and associated drawings describe exemplary embodiments in the context of certain example combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions can be provided by alternative embodiments without departing from the scope of the invention. In this regard, for example, combinations of elements and / or functions different from those explicitly described above are also contemplated within the scope of the invention. Therefore, although specific terminology is used herein, these terms are used only in a general and descriptive sense and not for limiting purposes.

Claims

1. A laser system for applying modifications to a sheet, the laser system comprising: The sheet; A first optical element, the first optical element having a first surface and a second surface; A laser configured to generate a laser beam directed toward a first surface of a first optical element, the laser beam having a first beam profile, wherein the first optical element is configured to cause the laser beam to travel to a second surface such that the laser beam has a second beam profile when it exits at the second surface, and such that the laser beam having the second beam profile is directed at the sheet and applies the modification to the sheet. as well as A rotary actuator configured to rotate the first optical element, wherein the rotary actuator is configured to rotate the first optical element by a first angle, and when the first optical element rotates by the first angle, the second beam profile rotates relative to the first beam profile by a second angle, and the second angle is at least about 1.5 times the first angle.

2. The laser system of claim 1, wherein the second angle is at least about twice the first angle.

3. The laser system according to any one of claims 1 or 2, wherein the modification is at least one of the following: cracks, refractive index modification, grooves, voids, densification, changes in chemical bonding in the sheet, melting, or color centers in the sheet.

4. The laser system according to any one of claims 1 or 2, wherein the modification defines an internal feature in the sheet, and the internal feature has a cross-sectional edge shape that is symmetrical about the optical axis.

5. The laser system according to claim 4, wherein the cross-sectional edge shape is a curved shape, a parabolic shape, a polygonal shape, or a shape comprising multiple linear segments.

6. The laser system according to any one of claims 4 to 5, wherein the laser beam is used to form a plurality of internal features in the sheet.

7. The laser system according to any one of claims 1 to 6, further comprising: A space shaping system configured to receive the laser beam to adjust the beam profile of the laser beam.

8. The laser system of claim 7, wherein the first beam profile is formed using the space shaping system.

9. The laser system according to any one of claims 7 or 8, wherein the space shaping system comprises at least one of: a fixed diffractive optical element, a phase plate, or another optical system configured to apply a rotating asymmetric amplitude or phase profile to the laser beam.

10. The laser system according to any one of claims 7 or 8, wherein the space shaping system comprises a spatial light modulator.

11. The laser system according to any one of claims 7 to 10, further comprising: One or more preparatory optical elements are configured to guide the laser beam into the space shaping system.

12. The laser system according to any one of claims 1 to 11, further comprising: A second optical element is configured to adjust the laser beam after it exits at the second surface of the first optical element.

13. The laser system of claim 12, wherein the second optical element is configured to focus the laser beam.

14. The laser system according to any one of claims 1 to 13, further comprising: A polarization control element configured to adjust the polarization of the laser beam.

15. The laser system according to any one of claims 1 to 14, wherein the laser beam is an Airy beam, a caustic beam, a Bessel beam, a multi-segment beam, or a multi-spot Gaussian beam.

16. The laser system according to any one of claims 1 to 15, wherein the sheet comprises glass.

17. The laser system according to any one of claims 1 to 16, wherein the first optical element defines a first optical axis, the laser beam is received at the first surface of the first optical element at a second optical axis, and there is a small linear offset between the first optical axis and the second optical axis.

18. The laser system according to any one of claims 1 to 17, wherein the laser beam is generated in bursts, and each burst of the bursts comprises a plurality of pulses.

19. The laser system according to any one of claims 1 to 18, wherein the first optical element is a Dove prism or a k-mirror assembly.

20. A method for modifying a sheet to form internal features in the sheet, the method comprising: Generate a laser beam; The laser beam is directed to a first optical element, the first optical element including a first surface and a second surface, wherein the laser beam is directed to the first optical element such that the laser beam is received at the first surface with a first beam profile, such that the laser beam is emitted at the second surface with a second beam profile, and such that the laser beam is directed to the sheet after emitting from the first optical element to produce the internal feature in the sheet; as well as While guiding the laser beam to the first optical element, the first optical element is rotated by a first angle, thereby creating the internal feature in the sheet. When the first optical element rotates the first angle, the second beam profile rotates a second angle relative to the first beam profile, and the second angle is at least about 1.5 times the first angle.

21. The method of claim 20, further comprising: During the formation of the internal features, the position of the sheet relative to the first optical element is adjusted; Generate a second laser beam; Guide the second laser beam to the first optical element; and The first optical element is rotated to create a second internal feature in the sheet.

22. The method according to any one of claims 20 to 21, wherein the laser beam is an Airy beam, a caustic beam, a Bessel beam, a multi-segment beam, or a multi-spot Gaussian beam.

23. A modified sheet material manufactured by the following method: Generate a laser beam; The laser beam is directed to a first optical element, the first optical element including a first surface and a second surface, wherein the laser beam is directed to the first optical element such that the laser beam is received at the first surface with a first beam profile, such that the laser beam is emitted at the second surface with a second beam profile, and such that the laser beam is guided from the second surface toward the sheet to create an internal feature in the sheet; as well as While guiding the laser beam to the first optical element, the first optical element is rotated by a first angle, thereby creating the internal feature in the sheet. When the first optical element rotates the first angle, the second beam profile rotates a second angle relative to the first beam profile, and the second angle is at least about 1.5 times the first angle.

24. The modified sheet of claim 23, wherein the method further comprises: During the formation of the internal features, the position of the sheet relative to the first optical element is adjusted; Generate a second laser beam; Guide the second laser beam to the first optical element; as well as The first optical element is rotated to create a second internal feature in the sheet.

25. The modified sheet according to any one of claims 23 to 24, wherein the laser beam is an Airy beam, a caustic beam, a Bessel beam, a multi-segment beam, or a multi-spot Gaussian beam.

Images