Fiber laser welding to a substrate

Abstract

A system for optical fiber laser welding to a substrate is provided. The system includes an optical fiber having a first end, a substrate defining a surface, a coating, a laser configured to emit photon energy, one or more processors, and a memory. The memory contains computer readable code configured to, upon execution, cause the one or more processors to perform various tasks. The tasks include positioning the optical fiber relative to the substrate such that the first end of the optical fiber is positioned proximate to the surface of the substrate, with the coating positioned between the optical fiber and the substrate. The tasks also include positioning the laser relative to the optical fiber or the substrate. The tasks also include causing the laser to emit photon energy through the optical fiber or through the substrate. The emission of the photon energy through the optical fiber or through the substrate causes the optical fiber to laser weld to the substrate.

Description

[0001] Priority application

[0002] This application claims priority to U.S. Provisional Application No. 63 / 547,039, filed November 2, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The embodiments generally involve fiber laser welding to a substrate. Background Technology

[0004] In attempting to directly splice optical fibers to photonic devices, some have tried fiber fusion splicing methods using electric arcs or carbon dioxide (CO2) lasers. However, these methods each have their own shortcomings. They are not efficient at splicing fibers to optical components of different shapes, and they face several challenges when attempting to form high-density interfaces.

[0005] Furthermore, conventional push-to-resist connectors are often insufficient for the high-density applications such as data centers. One-dimensional connectors relying on V-groove and ferrule fibers exist to support these applications, but two-dimensional arrays present a greater challenge. Typically, to provide precise alignment, holes must be drilled in the lens substrate and the fiber placed in each of these holes, but this technique faces challenges when scaling up the array to a large number of fibers.

[0006] Others have attempted to use carbon dioxide (CO2) lasers, where fibers are aligned one-to-one with the CO2 laser and welded using the laser. While this method can fabricate large quantities of two-dimensional arrays, it also has drawbacks. Currently available CO2 lasers can only act at the sides of the fiber at an angle relative to the central axis extending through it, due to the high absorption coefficients of the fiber and glass surfaces. This makes laser welding with CO2 lasers challenging for several reasons. First, it is challenging due to the shielding caused by adjacent fibers. Second, laser welding with CO2 lasers is challenging due to the non-uniform heating at the fiber-substrate interface caused by angular excitation. Because of this non-uniform heating, some locations on the fiber tend to overheat.

[0007] Furthermore, while ultrafast laser methods are feasible in principle, they currently suffer from numerous limitations. Using ultrafast laser methods, the surfaces of the fiber and photonic device must be in very close contact with each other, with gaps between 0.1 and 0.2 micrometers, and distortion of the pulse duration through the transmission path must be minimized. Maintaining focus or spot size is also crucial for ultrafast laser methods, as these methods are highly sensitive to power density. Ultrafast laser methods present challenges when attempting to focus the beam using non-planar elements such as lens arrays and other similar components. Summary of the Invention

[0008] In various embodiments, an optical fiber is attached to a substrate using a laser welding method. In some embodiments, the optical fiber extends substantially orthogonally relative to the substrate. The optical fiber is directly welded to the substrate using an absorbing coating on the surface of an ultraviolet laser and a lens. In this respect, the coating material is disposed on the substrate. One or more lasers can be used to emit photon energy through the optical fiber and / or the substrate, wherein the photon energy from the laser provides uniform and symmetrical heating, for example, at the interface between the optical fiber and the substrate (e.g., the coating). Therefore, after sufficient photon energy is emitted, the coating material on the substrate can dissolve into the substrate, and the coating material can become transparent at the relevant wavelength of one or more lasers.

[0009] One or more lasers can be used to emit photon energy through an optical fiber and / or substrate, such that the photon energy reaches a coating disposed between the fiber and the substrate. This differs from the method using a CO2 laser, which, as described above, delivers photon energy laterally. By emitting photon energy through the optical fiber and / or substrate, welding can be performed in a more uniform manner with less fiber distortion.

[0010] Furthermore, the laser welding method described herein allows for the attachment of optical fibers to a substrate without the need for any epoxy resin or organic adhesives along the optical path of the fiber. This offers several advantages. First, the process of attaching the fiber to another substrate can be faster. Second, attaching the fiber to the substrate results in less degradation. Third, the fiber can be attached to another substrate without issues in the return signal, as back reflections are minimized. Fourth, better environmental stability is achieved. Additional advantages include the ability to achieve higher fiber density, greater complexity, and improved reliability.

[0011] Furthermore, while ultrafast laser methods require close contact between surfaces and minimal distortion of pulse duration through the transmission path, these limitations can be overcome using pulsed ultraviolet laser welding methods, especially with pulse lengths of only nanoseconds and when using metallic or other inorganic surface materials. Using these pulsed ultraviolet laser welding methods, the amount of distortion of the fiber and the material attached to the fiber due to the welding process is minimized. Additionally, using these pulsed ultraviolet laser welding methods, the laser-treated coating has minimal impact on the glass surface. This pulsed ultraviolet laser welding method can be extended to orthogonally bonding fibers to a variety of substrates. For example, the fiber can be bonded to a glass substrate comprising silica or another material, and the fiber can be bonded to a substrate in the form of a lens array, a single-focusing lens, a C-lens, or other optical element. Using the laser welding method described herein, any dissolved coating material has little or no effect on attenuation, and low insertion loss can be achieved due to the dissipation of the absorbing coating used to initiate the process. The laser welding method described herein can be used to perform fiber collimation in many different micro-optical devices.

[0012] In an example embodiment, a method for fiber laser bonding to a substrate is provided. The method includes positioning an optical fiber relative to the substrate such that a first end of the fiber is positioned close to a surface of the substrate, wherein a coating is disposed between the optical fiber and the substrate. The method further includes positioning a laser relative to the optical fiber or the substrate. Additionally, the method includes causing the laser to emit photon energy through the optical fiber or through the substrate. The emission of photon energy through the optical fiber or through the substrate enables fiber laser bonding to the substrate.

[0013] In some embodiments, the laser may be an ultraviolet laser. In some embodiments, the emission of photon energy can cause the coating to dissolve into the substrate and become transparent at the wavelength of the laser. In some embodiments, the laser may be configured to generate photon energy in the form of pulses lasting about 10 nanoseconds or less.

[0014] In some embodiments, the optical fiber may have a second end, the laser may be positioned close to the second end of the optical fiber, and the laser may emit photon energy through the optical fiber or through the substrate by emitting photon energy from the laser to the second end of the optical fiber.

[0015] In some embodiments, the laser may be positioned close to the substrate, and the laser may emit photon energy through the optical fiber or through the substrate by emitting photon energy from the laser through the substrate such that the photon energy then propagates from the substrate to a first end of the optical fiber.

[0016] In some embodiments, the method further includes using a power meter to monitor whether laser welding has been completed. Additionally, in some embodiments, the method may further include a second laser configured to emit feedback photon energy, and the feedback photon energy may be directed toward the coating such that at least a portion of the feedback photon energy is redirected to the power meter.

[0017] In some embodiments, the method further includes configuring at least one optical element such that the at least one optical element receives photon energy from a laser and directs the photon energy toward an optical fiber or a substrate. Additionally, in some embodiments, the at least one optical element may comprise at least one of a mirror, a lens, or a light-shielding plate.

[0018] In some embodiments, the optical fiber may also be configured to emit light outward from the optical fiber and toward the substrate in an optical path, wherein no epoxy resin or organic adhesive is disposed within the optical path. In some embodiments, the substrate may have a material with a melting temperature lower than that of silica.

[0019] In some embodiments, the coating may be an inorganic thin coating having a thickness of less than about 100 nanometers. Additionally, in some embodiments, the coating may be configured to absorb photon energy at the wavelength of the laser with an absorption rate of at least about 30%. Furthermore, in some embodiments, the coating may become transparent at the wavelength of the laser after the laser is activated.

[0020] In some embodiments, the coating may be a metallic coating. Alternatively, the coating may include stainless steel or copper. In some embodiments, the optical fiber may be disposed relative to the substrate such that the spindle of the optical fiber at its first end is orthogonal to the surface of the substrate.

[0021] In another example embodiment, a non-transitory computer-readable medium is provided for fiber laser bonding to a substrate. The non-transitory computer-readable medium has software instructions stored thereon that, when executed by one or more processors, cause the one or more processors to perform various tasks. The tasks include positioning an optical fiber relative to the substrate such that a first end of the optical fiber is positioned close to a surface of the substrate, wherein a coating is disposed between the optical fiber and the substrate. The tasks also include positioning a laser relative to the optical fiber or the substrate, and causing the laser to emit photon energy through the optical fiber or through the substrate. The emission of photon energy through the optical fiber or through the substrate causes the fiber laser to bond to the substrate. In some embodiments, the coating may be a thin inorganic metallic coating having a thickness of less than about 100 nanometers.

[0022] In another example embodiment, a system for fiber laser bonding to a substrate is provided. The system includes an optical fiber having a first end, a substrate defining a surface, a coating, a laser configured to emit photon energy, one or more processors, and a memory. The memory contains computer-readable code configured to cause the one or more processors to perform various tasks upon execution. The tasks include positioning the optical fiber relative to the substrate such that the first end of the optical fiber is positioned proximate to the surface of the substrate, wherein a coating is disposed between the optical fiber and the substrate. The tasks also include positioning the laser relative to the optical fiber or the substrate, and causing the laser to emit photon energy through the optical fiber or through the substrate. The emission of photon energy through the optical fiber or through the substrate causes the fiber laser to bond to the substrate.

[0023] In some embodiments, the laser may be an ultraviolet laser configured to generate photon energy in pulses. In some embodiments, the coating may be a thin inorganic metal coating having a thickness of less than about 100 nanometers. In some embodiments, the optical fiber may be configured to emit light outward from the optical fiber and toward the substrate in an optical path, wherein no epoxy resin or organic adhesive is disposed within the optical path.

[0024] In another example embodiment, an optical fiber assembly is provided, which is fabricated by a specific process. The process includes positioning an optical fiber relative to a substrate such that a first end of the fiber is positioned close to a surface of the substrate, wherein a coating is disposed between the optical fiber and the substrate. The process also includes positioning a laser relative to the optical fiber or the substrate, and causing the laser to emit photon energy through the optical fiber or through the substrate. The emission of photon energy through the optical fiber or through the substrate enables fiber laser bonding to the substrate. Attached Figure Description

[0025] Please refer to the accompanying drawings, which may not be drawn to scale, and in which:

[0026] Figures 1A to 1C This is a schematic diagram illustrating an example system for bonding fiber laser to a substrate according to some embodiments discussed herein;

[0027] Figure 2 This is a schematic diagram illustrating an example optical fiber assembly in which photon energy is extended through an optical fiber or a substrate in the form of a lens, according to some embodiments discussed herein;

[0028] Figure 3 This is a schematic diagram illustrating an example optical fiber assembly in which light extends through an optical fiber or a substrate in the form of a lens array, according to some embodiments discussed herein;

[0029] Figure 4 This is a perspective view showing an example fiber optic assembly with the fiber optic cable soldered to a substrate according to some embodiments discussed herein;

[0030] Figures 5 to 6 This is an enhanced image showing an example fiber optic assembly with the fiber optic cable soldered to a substrate according to some embodiments discussed herein;

[0031] Figure 7 This is a transmission electron microscope (TEM) image showing an example coating placed on a substrate prior to laser processing, according to some embodiments discussed herein;

[0032] Figure 8 This illustrates the laser treatment following some embodiments discussed herein. Figure 7 TEM images of a substrate in which coating material is integrated;

[0033] Figure 9 This is a graph showing the signal strength of optical fibers orthogonally extended relative to the substrate and optical fibers extending along the surface of the substrate at different angles according to some embodiments discussed herein.

[0034] Figure 10 This is a graph illustrating an example far-field distribution of an optical fiber on a substrate including Corning EAGLE SG Slim Glass according to some embodiments discussed herein, wherein the substrate is welded using an ultraviolet laser and wherein the optical fiber extends orthogonally to the surface of the substrate.

[0035] Figure 11 This is a graph illustrating an example far-field distribution of an optical fiber on a substrate comprising Corning EAGLE SG ultrathin glass according to some embodiments discussed herein, wherein the substrate is welded using an ultraviolet laser and wherein the optical fiber extends along the surface of the substrate.

[0036] Figure 12 This is a graph showing the amount of absorption caused by the presence of different metal coatings according to some embodiments discussed herein;

[0037] Figure 13 This is a block diagram illustrating various components of a system for bonding fiber laser to a substrate according to some embodiments discussed herein; and

[0038] Figure 14 This is a flowchart illustrating an example method for welding fiber laser to a substrate according to some embodiments discussed herein. Detailed Implementation

[0039] Exemplary embodiments will now be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, embodiments. Similar reference numerals generally refer to similar elements throughout. For example, reference numerals 114, 114', 114", 414, and 514 each refer to a substrate. As used herein, photon energy and optical intent are used interchangeably. Furthermore, unless specifically stated otherwise, any connection or attachment may be a direct or indirect connection or attachment.

[0040] Figure 1A This is a schematic diagram illustrating an example system 100 for bonding optical fibers to a substrate 114. System 100 includes lasers 102A and 102B. Lasers 102A and 102B are ultraviolet lasers. Laser 102A can operate in continuous wave mode at a wavelength of about 1310 nm or about 1550 nm with a power of several megawatts, and laser 102B can operate at a wavelength of about 355 nm with a frequency of about 2 MHz. Laser 102B can also generate photon energy in the form of pulses of about 10 nanoseconds, about 5 nanoseconds, or about 2 nanoseconds. Laser 102B and other lasers described herein can be high-repetition ultraviolet lasers, and the use of these lasers may be crucial because they produce sufficient absorption in the metallic coating and surrounding glass without causing ablation of material properties that could be achieved using nanosecond pulsed lasers with low repetition rates of less than 100 MHz. However, other lasers operating at different wavelengths, frequencies, and / or pulse lengths can be utilized. Alternatively, the laser can be a continuous-wave laser, which provides photon energy continuously while in operation, rather than in pulses. Laser 102A can be attached to coupler 106 along with power meter 104, which will be discussed further herein. Laser 102B typically operates at an average power of only a few watts.

[0041] exist Figure 1A In this embodiment, an optical fiber is provided comprising a first optical fiber portion 108, a second optical fiber portion 112, and another optical fiber portion disposed in an optical fiber reel 110. However, in other embodiments, the optical fiber reel 110 may be omitted, and the optical fiber may extend in different directions. Figure 1A The optical fiber and other optical fibers described herein may be telecommunications optical fibers or optical fibers. A first end 108A of the optical fiber is disposed at the end of the first optical fiber portion 108, and a second end 112A of the optical fiber is disposed at the end of the second optical fiber portion 112.

[0042] System 100 also includes a substrate 114. Substrate 114 may comprise a material with a melting temperature below that of silicon, and in some embodiments, substrate 114 may comprise molten silicon. Substrate 114 may be a lens array, a single-focusing lens, a C-lens, or some other type of optical element. Although substrate 114 is generally flat, the laser welding techniques described herein can still be used with other substrates that are not flat. Coating 113 is disposed on the surface of substrate 114 between the second fiber portion 112 of the optical fiber and substrate 114. This coating 113 may be an inorganic thin coating. Alternatively, coating 113 may comprise a metallic coating, such as stainless steel or copper. In some embodiments, coating 113 may have a thickness of less than 100 nanometers or even less than 90 nanometers. In the illustrated embodiment, coating 113 has a thickness of approximately 80 nanometers. Coating 113 may also be configured to absorb photon energy at the wavelength of laser 102B with an absorptivity of at least 30%.

[0043] The optical fiber defines a main axis A1 at its second end 112A, which is orthogonal to the surface of the substrate 114 and the surface 113A of the coating 113 on the substrate 114. However, in other embodiments, the optical fiber may be configured such that the second end 112A is not orthogonal to the surface 113A.

[0044] System 100 also includes a first optical element 118, a second optical element 122, and a third optical element 123. The first optical element 118 is a reflector, the second optical element 122 is a lens, and the third optical element 123 is a light-shielding plate. However, in other embodiments, various other optical elements may be used. Furthermore, in other systems, optical elements may not be used, or a different number of optical elements may be used.

[0045] During operation, the coating 113 is deformed using photon energy from laser 102B. When laser 102B is activated, some of the photon energy is absorbed by coating 113, and coating 113 eventually becomes transparent to photon energy emitted by laser 102B, allowing photon energy to extend through coating 113. Coating 113 becomes transparent at the wavelength of laser 102B (e.g., at wavelengths between approximately 300 nanometers and approximately 1700 nanometers).

[0046] When activated, laser 102B emits photon energy toward optical element 123. The photon energy emitted by laser 102B can have a higher power level than that emitted by laser 102A. For example, laser 102A can operate at a power level of less than about 1 megawatt, and laser 102B can operate at a power level of greater than about 100 megawatts. The photon energy passes through optical element 123 and extends along optical path 150 toward optical element 122. Optical element 122 guides the photon energy passing through optical path 150, causing the photon energy to begin propagating along optical path 120. Optical element 122 focuses the photon energy to achieve the higher power density required to melt coating 113 and / or substrate 114. The photon energy propagating along optical path 120 then extends to optical element 118. Optical element 118 then guides the photon energy passing through optical path 120, causing the photon energy to begin propagating along optical path 116. Photon energy propagating along optical path 116 is directed through substrate 114, allowing it to reach coating 113. A portion of this photon energy is absorbed by coating 113, especially before laser welding is complete. As more photon energy is absorbed by coating 113, it becomes more transparent, allowing more photon energy to pass through. The photon energy emitted by laser 102B is mismatched with the optical fiber in terms of numerical aperture, thus causing minimal coupling at the fiber.

[0047] During operation, laser 102A is generally used to provide low-power photon energy, which is configured to be reflected back toward power meter 104 to allow determination of when laser welding has been completed. Laser 102A is activated such that the low-power photon energy from laser 102A is directed through coupler 106. Coupler 106 is configured to direct the photon energy directly into the fiber at a first end 108A. Once the photon energy has been introduced into the fiber at the first end 108A, the photon energy extends through the fiber until it exits at a second end 112A. After exiting at the second end 112A, the photon energy is directed to coating 113. While laser welding is not yet complete, a portion of the photon energy from laser 102A may be absorbed by coating 113 on substrate 114, and another portion of the photon energy from laser 102A may be reflected back into the fiber. Next, the reflected photon energy travels through the optical fiber back to coupler 106, whereby the reflected photon energy is directed to power meter 104. The reflected signal received at power meter 104 depends on the refractive index difference between the optical fiber and the component immediately adjacent to the second end 112A of the optical fiber. While laser welding is not yet complete, the returned signal can be approximately -14 dB or higher. Upon completion of laser welding, if substrate 114 comprises Corning EAGLE SG ultrathin glass, the returned signal can be less than approximately -35 dB, or if substrate 114 comprises silicon, the returned signal can be less than approximately -55 dB. However, if substrate 114 comprises other materials, the returned signal may differ further. Upon completion of laser welding, coating 113 becomes more transparent, allowing more photon energy to be emitted through the coating and causing less photon energy to be reflected back to power meter 104. Therefore, upon completion of laser welding, the returned signal received at power meter 104 is lower.

[0048] Coupler 106 can be a 3 dB coupler, and power meter 104 can be configured to monitor the return signal by measuring the amount of photon energy returning through the optical fiber. The attachment of the optical fiber to the substrate can be controlled by the return signal at power meter 104. When the return signal at power meter 104 drops below approximately -20 to -30 dB, it can be determined that the laser welding of the optical fiber is complete, and the laser can be turned off or advanced to another optical fiber. The return signal may be affected by reflections from the back surface of the substrate, and the return signal may also be affected by refractive index mismatch between the optical fiber, coating, and substrate materials. Although in Figure 1A The coating 113 is shown as being distributed across the entire top surface of the substrate 114, but in other embodiments, the coating 113 may alternatively be disposed on a smaller portion of the surface of the substrate 114. Although in Figure 1AThe illustrated system 100 utilizes a power meter 104, but the power meter may be omitted from other embodiments. Alternatively, the power meter 104 can be used to determine the appropriate amount of photon energy needed to be emitted for one fiber, and the laser can then emit the determined amount of photon energy for other fibers without using the power meter 104.

[0049] Other alternative layouts can be used to form the system, such as Figure 1A The system shown is an example. Figure 1B The alternative system 100' is shown in the diagram. Similar to... Figure 1A System 100, system 100' includes a laser 102A', a laser 102B', a power meter 104', a coupler 106', an optical fiber 112' having a first end 108A' and a second end 112A', a coating 113', a substrate 114', an optical element 122' in the form of a lens, and another optical element 123' in the form of a light shield. Each of these components may be substantially similar to Figure 1A The corresponding components.

[0050] During operation, the coating 113' is deformed using photon energy from the laser 102B'. When the laser 102B' is activated, some of the photon energy can be absorbed by the coating 113', and the coating 113' eventually becomes transparent to the photon energy emitted by the laser 102B', allowing the photon energy to extend through the coating 113'. The coating 113' can become transparent at the wavelength of the laser 102B' (e.g., at wavelengths between approximately 300 nanometers and approximately 1700 nanometers).

[0051] When activated, laser 102B' emits photon energy toward optical element 123'. The photon energy emitted by laser 102B' can have a higher power level than that emitted by laser 102A'. The photon energy can pass through optical element 123' and extend along optical path 150' toward optical element 122'. Optical element 122' guides the photon energy passing along optical path 150', causing the photon energy to begin propagating along optical path 116'. Optical element 122' focuses the photon energy to achieve the higher power density required to melt coating 113' and / or substrate 114'. The photon energy propagating along optical path 116' is guided through substrate 114', causing the photon energy to reach coating 113'. A portion of this photon energy can be absorbed by coating 113', especially before laser welding is complete. As more photon energy is absorbed by coating 113', coating 113' becomes more transparent to allow more photon energy to pass through coating 113'. The photon energy emitted by laser 102B' is mismatched with the numerical aperture value of fiber 112', and therefore this photon energy causes minimum coupling at fiber 112'.

[0052] During operation, laser 102A' can also be activated, and photon energy from laser 102A' can be guided through coupler 106' and into optical fiber 112' at the first end 108A'. Coupler 106' can be configured to directly guide photon energy into optical fiber 112' at the first end 108A'. Once photon energy has been introduced into optical fiber 112', it can extend through optical fiber 112' until it exits at the second end 112A' of optical fiber 112'.

[0053] While laser welding is not yet complete, a portion of the photon energy from laser 102A' is absorbed by coating 113' on substrate 114', and another portion of the photon energy from laser 102A' is reflected back into optical fiber 112'. The reflected photon energy then extends back through optical fiber 112' and reaches coupler 106', allowing it to be guided to power meter 104'. The reflected signal received at power meter 104' depends on the refractive index difference between the optical fiber and the component immediately adjacent to the second end 112A' of optical fiber 112'. While laser welding is not yet complete, the returned signal can be approximately -14 dB or lower. Upon completion of laser welding, if substrate 114' comprises Corning EAGLE SG ultrathin glass, the returned signal can be less than approximately -35 dB, or if substrate 114' comprises silicon, the returned signal can be less than approximately -50 dB. However, the returned signal may differ further if substrate 114' comprises different materials. Upon completion of laser welding, coating 113 can become more transparent, allowing more photon energy to be emitted through the coating and causing less photon energy to be reflected back to power meter 104'. Therefore, the returned signal received at power meter 104' may be lower upon completion of laser welding.

[0054] The optical fiber 112' defines a main axis A2 at its second end 112A', wherein the main axis A2 is orthogonal to the surface of the substrate 114' and the surface 113A' of the coating 113' on the substrate 114'. However, in other embodiments, the optical fiber 112' may be configured such that the first end 108A' is not orthogonal to the surface 113A'. Figure 1B System 100' and Figure 1A The difference between system 100 and system 100' is that system 100' does not contain any fiber optic reel 110, and system 100' contains only two optical elements. Although in Figure 1B The coating 113' is shown as being distributed across the entire top surface of the substrate 114', but in other embodiments, the coating 113' may alternatively be disposed on a smaller portion of the surface of the substrate 114'.

[0055] exist Figure 1CAnother alternative system 100 is shown in the diagram. Similar to... Figure 1A System 100 and Figure 1B The system 100" includes a laser 102B", an optical fiber 112" having a first end 108A" and a second end 112A", a coating 113", and a substrate 114". Figure 1C The difference between system 100" and other systems is that the laser 102B" is located on the side of the optical fiber 112" rather than on the side of the substrate 114". Therefore, any photon energy generated by the laser 102B" first propagates through the optical fiber 112" rather than through the substrate 112". In addition, system 100" does not have any optical components, does not have a second laser, does not have a coupler and does not have a power meter.

[0056] During operation, laser 102B" can be activated. Photon energy from laser 102B" is emitted directly into the first end 108A" of optical fiber 112". This photon energy extends through optical fiber 112" and exits at the second end 112A" of optical fiber 112". While laser welding is not yet complete, a portion of the photon energy from laser 102B" can be absorbed by coating 113" on substrate 114", and another portion of the photon energy from laser 102A" can be reflected back into optical fiber 112". In some embodiments, the reflected photon energy can extend back through optical fiber 112" and reach a power meter attached via a coupler to measure the amount of reflected photon energy, allowing the power meter to be used to determine when laser welding has been completed. However, in other embodiments, the completion of laser welding can be determined in other ways (e.g., by activating laser 102B" for a specified duration, by using other sensors, etc.).

[0057] The optical fiber 112" defines a main axis A3 at its second end 112A", wherein the main axis A3 is orthogonal to the surface of the substrate 114" and the surface 113A" of the coating 113" on the substrate 114". However, in other embodiments, the optical fiber 112" may be configured such that the second end 112A" is not orthogonal to the surface 113A". Figure 1A System 100 Figure 1B System 100' and Figure 1C The configuration used in System 100 is merely exemplary, and it should be understood that various alternative configurations are also envisioned.

[0058] Laser welding can be used to attach optical fibers to various types of substrates, and Figure 2Two example fiber optic assemblies are shown in which fiber laser welding is performed onto a substrate in the form of a lens. Fiber optic assembly 238A includes an optical fiber 212 and a substrate 236, wherein a coating 234 is disposed between the optical fiber 212 and the substrate 236. The substrate 236 is a C-lens type device, but other types of lenses can be used instead of the substrate 236. Laser welding can be performed effectively even if the substrate 236 is not flat.

[0059] exist Figure 2 In the fiber optic assembly 238A, photon energy 232A can be emitted into the fiber 212 at the first end 208A. In doing so, the photon energy can propagate through the fiber 212 and exit at the second end 212A. This photon energy can be partially absorbed at the coating 234 as described above.

[0060] like Figure 2 As shown in the fiber optic assembly 238B, photon energy 232B can also be emitted from the opposite direction, wherein photon energy 232B propagates through substrate 236 before reaching coating 234. For both fiber optic assemblies 238A and 238B, the wavelength of the light may depend on the materials used for fiber optic 212, coating 234, and / or substrate 236.

[0061] When substrate 236 comprises molten silicon, ultraviolet photon energy can be used with radiation of approximately 355 nanometers and a high repetition rate. For glass materials with lower melting temperatures, other wavelengths, such as infrared (IR) or near-infrared (NIR) wavelengths, may be suitable. Furthermore, for glass materials with lower melting temperatures, photon energy can be provided in pulsed or continuous wave form. Figure 2 In the fiber optic assemblies 238A and 238B, examples are provided in which the fiber optic 212 does not extend completely orthogonally relative to the surface of the substrate 236, and the laser welding method described herein can still operate effectively with some deviation from the completely orthogonal orientation of the fiber optic 212.

[0062] Similarly, photon energy can be emitted through fiber arrays to weld fiber lasers to a substrate, and these fiber arrays can be densely stacked. Figure 3Two fiber optic assemblies 340A and 340B are shown, wherein photon energy is guided into the optical fibers of the fiber optic assemblies 340A and 340B in different ways. In fiber optic assembly 340A, an array of four optical fibers is provided, wherein the array includes optical fibers 312A to 312D. Fiber optic assembly 340A also includes a substrate 336 in the form of a lens array and a coating 334 disposed between the substrate 336 and the optical fibers 312A to 312D. The coating 334 may be provided in the form of a film. The substrate 336 may be a gradient refractive index (GRIN) lens attachment, but in other embodiments, other lenses may be used instead of a GRIN lens attachment. Photon energy may be emitted sequentially through the optical fibers 312A to 312D, wherein photon energy is first emitted at position 332A. Figure 2 The photon energy is emitted through fiber 212 of fiber optic assembly 238A in a similar manner to that emitted through fiber 312A of fiber optic assembly 340A. Once it is no longer necessary to continue emitting photon energy at fiber 312A, the laser can be moved to position 332A' to emit photon energy at fiber 312B, and the laser can eventually be moved to other positions to emit photon energy into other fibers 312C, 312D in fiber optic assembly 340A.

[0063] In the fiber optic assembly 340B, an array of four optical fibers is provided, wherein the array includes optical fibers 312A to 312D. The fiber optic assembly 340B also includes a substrate 336 in the form of a lens array and a coating 334 disposed between the substrate 336 and the optical fibers 312A to 312D. Photon energy can be emitted through the substrate 336, such that the photon energy extends into the coating 334 in regions close to the respective optical fibers. The photon energy is first emitted at position 332B. Figure 2 The photon energy is emitted through the substrate 236 of the fiber optic assembly 238B in a similar manner to that emitted through the substrate 336 of the fiber optic assembly 340B. Once it is no longer necessary to continue emitting photon energy toward the coating 334 near the fiber optic 312A, the laser can be moved to position 332B' to emit photon energy toward the coating 334 near the fiber optic 312B, and the laser can eventually be moved to other positions to emit photon energy toward the coating 334 near other fibers 312C, 312D in the fiber optic assembly 340B. Although fiber optic assemblies 340A and 340B contain linear fiber arrays, other fiber optic assemblies may contain two-dimensional fiber arrays.

[0064] Figure 4This is a perspective view showing the fiber optic assembly 425 after the fiber optic cable 412 has been laser-welded to the substrate 414. The substrate 414 is formed by providing a stainless steel coating with a thickness of approximately 40 nanometers to the surface of the glass substrate. The initial glass substrate is display glass in the form of Corning EAGLE SG ultrathin glass, but other glass substrates may also be used. Corning EAGLE SG ultrathin glass includes a low melting temperature of approximately 800 degrees Celsius and approximately 32 × 10⁻⁶ mm². -7 Corning EAGLE SG ultrathin glass has a relatively low melting temperature and a relatively high coefficient of thermal expansion compared to substrates containing fused silica. These properties allow Corning EAGLE SG ultrathin glass to experience less distortion compared to other substrates containing fused silica. Additionally, due to the difference in coefficient of thermal expansion and melting temperature, Corning EAGLE SG ultrathin glass can be soldered with less power compared to substrates containing fused silica. In the case of Corning EAGLE SG ultrathin glass, the power level can be approximately 1 to 1.5 watts, and the total exposure time can be approximately 0.5 seconds. Since soldering with a fused silica substrate requires more power, the likelihood of distortion in the optical fiber and / or substrate increases. However, in some embodiments, substrates containing fused silica can still be used (see, for example...). Figure 6 Furthermore, other materials can be used to replace Corning EAGLE SG ultrathin glass.

[0065] In some embodiments, the fiber optic assembly 425 may include an adhesive 424 surrounding the fiber optic cable 412. This adhesive 424 may be introduced after the fiber optic cable 412 has been laser-bonded to the substrate 414. By doing so, the adhesive 424 may not be present in any optical path of the fiber optic cable 412. The bond between the fiber optic cable 412 and the substrate 414 is strong enough to allow the fiber optic cable 412 to be used to lift the substrate 414. Laser bonding of the fiber optic cable to the substrate can be performed to achieve good optical contact between the center of the fiber optic cable and the substrate.

[0066] exist Figure 5 The enhanced image shows another example of an optical fiber assembly 525, which includes an optical fiber 512 soldered to a substrate 514. The optical fiber assembly 525 may be disposed on supports 526A, 526B, while the optical fiber 512 is soldered to the substrate 514 using photonic energy. However, in Figure 5In this assembly, optical fiber 512 is used to lift substrate 514 upwards from supports 526A and 526B. Optical fiber assembly 525 includes adhesive 524 surrounding optical fiber 512. Adhesive 524 is Norland Optical Adhesive Type 61, which is UV-curable, but other adhesives may also be used. This adhesive 524 can be introduced after optical fiber 512 has been bonded to substrate 514 using photon energy. By doing so, adhesive 524 is not present in any optical path of optical fiber 512, thus allowing light to propagate more efficiently from optical fiber 512. Adhesive 524 also provides mechanical stability to the sample.

[0067] exist Figure 6 The enhanced image shows another example of an optical fiber assembly 625, where the substrate 614 comprises fused silica. The optical fiber assembly 625 includes an optical fiber 612 soldered to the substrate 614. The optical fiber assembly 625 may be disposed on supports 626A, 626B, while the optical fiber 612 is soldered to the substrate 614 using photonic energy. The optical fiber 612 is SMF-28 Ultra Corning fiber. However, other optical fiber assemblies may include different materials within the substrate and the optical fiber. To optimize the optical fiber assembly 625, it may be advantageous to adjust the thickness of any coatings on the substrate prior to laser soldering. Figure 6 In substrate 614, the initial coating has a thickness of approximately 80 nanometers, and after laser welding, this coating can ultimately form a metal seal within substrate 614. When molten silicon is used in substrate 614, the power required for welding at the laser can be increased to approximately 2 to 3 watts, and the total exposure time can be approximately 0.5 seconds.

[0068] Laser welding can help form metal seals in a substrate by applying a coating to the substrate and exposing the coating to photon energy. Figure 7 This is a TEM image showing an example coated substrate 735 before laser welding, and... Figure 8 This is a TEM image showing an example coated substrate 835 after laser welding. Prior to laser welding, the coated substrate 735 includes a coating 734 disposed on a substrate 732. The coating 734 is an SS-304 stainless steel coating, but in other embodiments, the coating 734 may be another metal coating, such as another form of stainless steel copper. The coating 734 may have an initial thickness A1 of about 20 nanometers, but other thicknesses may be used for the coating 734 prior to laser welding. Other types of coatings may be used alternatively. Similarly, in some embodiments, the substrate 732 may include glass, but the substrate 732 may include other materials, such as transparent materials.

[0069] After sufficient laser processing, the material of coating 734 can form a seal 836 within substrate 838. Through laser welding, the initial coating 734 is effectively fragmented into nanoparticles with diameters well below 100 nanometers. During the dynamic welding dwell time, these nanoparticles effectively dissolve and migrate into the interfacial molten glass substrate. These nanodroplets in the weld area are transparent to the eye because their size is well below the Mie scattering limit. The formed seal 836 may comprise a metallic material and may be dispersed throughout the glass substrate 738 at a thickness A2. In some embodiments, the thickness A2 may be approximately 250 nanometers, but other values ​​are possible.

[0070] Even when the optical fiber is laser-welded to extend orthogonally relative to the substrate, the optical fiber exhibits only a limited amount of distortion. Figure 9 This is a graph showing the signal strength of an optical fiber extending orthogonally relative to the substrate and an optical fiber extending along the surface of the substrate at different angles. The far-field images and distribution can be used to measure the intensity distribution of the assembly after the laser welding process has been completed. In the graph, the signal strength is presented on the y-axis, and the angle values ​​are presented on the x-axis. The signal strength can be obtained using a detector placed approximately 30 cm from the laser-welded fiber assembly, with a designed focal length of a few millimeters. At a relatively large detector distance of approximately 30 cm, the collimated beam begins to exhibit some divergence. The angle value is the angle of photon energy relative to the extension along the principal axis of the fiber. The shape of the far-field distribution corresponds to the mode of a single-mode fiber, and this is typically used to obtain the mode field diameter. However, any defects in the fiber or lens produced by laser welding can cause distortion, and this distortion can lead to a distortion of the far-field distribution. A far-field distribution without distortion will resemble a Gaussian two-dimensional distribution. Without a lens, the divergence is typically high, and with a lens, the fiber radiation output is almost collimated. For curves 928 and 930, the fiber is bonded perpendicular to the substrate. However, measurements are performed on two different axes to evaluate the two-dimensional intensity distribution. In the absence of distortion, the two-dimensional intensity distribution should be centered at 0 radians. For both curves 928 and 930, the wavelength is approximately 1550 nm. Figure 9 The curves 928 and 930, derived from a Gaussian distribution, illustrate the finite distortion caused by the finite laser welding process. Minimizing distortion is crucial for achieving low insertion loss due to focal spot variations when the component incorporates lensing devices and pointing directions.

[0071] Figure 10This is a graph showing an example far-field distribution of optical fibers on a display glass in the form of Corning EAGLE SG ultra-thin glass, where the fibers are welded in a vertical orientation using an ultraviolet laser. Figure 10 The graph shows the logarithmic amplitude in decibels on the y-axis and the angle in radians on the x-axis. The angle is the angle of the photon energy relative to the principal axis extending through the optical fiber. Figure 10 The graph includes curve 1040. For angles up to approximately -0.6 radians, curve 1040 generally remains at about 8 dB. However, curve 1040 begins to increase at a greater rate around the -0.6 radian angle, with a logarithmic amplitude of about 10 dB around the -0.5 radian angle, about 20 dB around the -0.25 radian angle, and about 55 dB around the -0.125 radian angle. The logarithmic amplitude peaks at approximately 63 dB, which is the highest point at angles just below 0.0 radians. Next, curve 1040 begins to decrease rapidly, exhibiting a logarithmic amplitude of approximately 40 dB around an angle of 0.125 radians, approximately 16 dB around an angle of 0.25 radians, approximately 10 dB around an angle of 0.5 radians, and approximately 7 dB around an angle of 1.0 radians. Curve 1040 generally displays a Gaussian shape indicating minimal distortion, suggesting minimal distortion caused by the laser process. This can help ensure low insertion loss when using lensed fibers.

[0072] Figure 11 This is a graph illustrating an example far-field distribution of optical fibers on a display glass in the form of a Corning EAGLE SG ultrathin glass substrate, where the fibers are welded in a horizontal orientation using an ultraviolet laser. Similar to... Figure 10 The curve graph, Figure 11 The graph shows the logarithmic amplitude in decibels on the y-axis and the angle in radians on the x-axis. The angle is the angle of photon energy relative to the principal axis extending through the optical fiber. [The process involves] generating... Figure 11 The curve was tested to verify the distortion of the expected Gaussian distribution for the "undisturbed" fiber attached to the lens. Figure 11The graph includes curve 1142. Curve 1142 has an amplitude of approximately 17 dB at an angle of -1.5 radians. Curve 1142 gradually increases to a logarithmic amplitude of approximately 21 dB at an angle of approximately -1.0 radians, and further increases to a logarithmic amplitude of approximately 25 dB at an angle of approximately -0.33 radians. The logarithmic amplitude then rapidly increases to a peak of approximately 63 dB at an angle of approximately 0.10 radians, and then rapidly decreases to approximately 24 dB at an angle of approximately 0.35 radians. Curve 1142 then gradually decreases to a logarithmic amplitude of approximately 17 dB at an angle of approximately 1.5 radians.

[0073] Typical insertion loss due to the presence of the substrate coating is less than about 0.1 dB, therefore the coating is essentially transparent. Typical return loss due to reflection at the interface between the optical fiber and the silicon substrate is less than about -55 dB to about -60 dB, and this indicates that the two parts form an optical contact without refractive index mismatch, as the measured noise floor is about -60 dB.

[0074] Figure 12 This is a graph showing the absorption caused by the presence of a metallic coating. For Figure 12 The percentage of absorption is shown on the y-axis, and the wavelength is shown in nanometers on the x-axis.

[0075] in addition, Figure 12 Four different curves are shown. Curve 1244 shows the result of an initial coating including stainless steel. Curve 1246 shows the result of an initial coating including titanium. Curve 1248 shows the result of an initial coating including an alloy containing nickel and aluminum. Curve 1250 shows the result of an initial coating including chromium, nickel, and oxygen.

[0076] As shown, curve 1244 (for initial coatings including stainless steel) has the highest absorption percentage, with the absorption percentage remaining at approximately 90% regardless of wavelength. Curve 1246 (for initial coatings including titanium) has the second highest absorption percentage, with the absorption percentage remaining between approximately 65% ​​and 70% regardless of wavelength. Curve 1248 (for initial coatings including nickel and aluminum) has the third highest absorption percentage, with the absorption percentage remaining at approximately 64% regardless of wavelength, and the absorption percentage of curve 1248 is lower than that of curve 1246. Curve 1250 (for initial coatings including chromium, nickel, and oxygen) has the fourth highest absorption percentage, with the absorption percentage remaining between approximately 32.5% and 40%.

[0077] While the coating may include the materials mentioned above, other materials may also be used in the coating. For example, the coating may include chromium, titanium, aluminum, nickel, copper, and / or stainless steel, alone or in combination. In some embodiments, the coating may include a combination of stainless steel and aluminum, a combination of titanium and copper, or a combination of stainless steel and copper.

[0078] The coating can have various thicknesses. For example, the coating can have a thickness between about 20 nanometers and about 150 nanometers, between about 40 nanometers and about 130 nanometers, between about 60 nanometers and about 110 nanometers, and between about 70 nanometers and about 90 nanometers. In various embodiments, a coating with a thickness of about 80 nanometers can be used.

[0079] Figure 13 This is a block diagram illustrating example components of a system 1380 for bonding optical fibers to a substrate. System 1380 includes one or more lasers 1302, one or more power meters 1304, one or more actuators 1352, one or more processors 1354, one or more memory devices 1356, one or more optical elements 1358, and one or more position sensors 1360.

[0080] One or more lasers 1302 may be ultraviolet lasers, operating, for example, at a wavelength of about 355 nanometers and a frequency of about 2 MHz, with one or more lasers 1302 generating photon energy in pulses of about 2 nanoseconds in length. One or more lasers 1302 and other lasers described herein may be high-repetition ultraviolet lasers, and the use of these lasers may be crucial because they generate sufficient absorption in the metallic coating and surrounding glass without causing ablation of material properties that could be achieved using nanosecond pulsed lasers with low repetition rates of less than 100 MHz. However, one or more lasers 1302 may have other forms and may operate at different wavelengths, frequencies, and pulse lengths. Alternatively, one or more lasers 1302 may be continuous-wave lasers, providing photon energy continuously while in operation, rather than in pulses. Additionally, in some embodiments, one or more lasers 1302 may be configured to generate photon energy in pulses, with pulses lasting 10 nanoseconds or less. One or more power meters 1304 can be configured to monitor the return signal by measuring the amount of photon energy returning through the optical fiber.

[0081] One or more optical elements 1358 can be used to redirect photon energy to different directions, allowing photon energy to be efficiently guided into the optical fiber. The one or more optical elements 1358 can be provided in the form of mirrors, lenses, or light-shielding plates, but other optical elements may also be used.

[0082] One or more actuators 1352 can be used to adjust the position and / or orientation of one or more components. For example, if different directions of photon energy relative to an optical fiber are desired, one or more actuators 1352 can be used to adjust the position and / or orientation of the optical fiber, one or more optical elements 1358, one or more lasers 1302, or other components. One or more position sensors 1360 can also be used. One or more position sensors 1360 can be used to detect the position and / or orientation of optical fibers, lasers, optical elements, power meters, etc. In some embodiments, one or more actuators 1352 can be used to adjust the position and / or orientation of components based on measurements obtained by one or more position sensors 1360.

[0083] Memory 1356 may contain computer-readable instructions stored in memory 1356. These computer-readable instructions may be provided in the form of computer code. When executed by one or more processors 1354, the computer-readable instructions may cause one or more processors 492 to perform any of the methods described herein.

[0084] In an example embodiment, memory 1356 may include one or more non-transitory storage media or memory devices, such as fixed or removable volatile and / or non-volatile memory. Memory 1356 may be configured to store instructions, computer program code, and other related data in a non-transitory computer-readable medium for use by, for example, one or more processors 1354 to perform various functions according to example embodiments of the invention. For example, memory 1356 may be configured to buffer input data for processing by one or more processors 1354. Alternatively or additionally, memory 1356 may be configured to store instructions for execution by one or more processors 1354.

[0085] One or more processors 1354 may be any component configured to execute various programmed operations or instructions stored in a memory device (e.g., memory 1356), such as a device or circuit system implemented in software operation or otherwise in hardware or a combination of hardware and software (e.g., a processor operating under software control, or a processor implemented as a specific 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 the device or circuit system to perform the corresponding functions of one or more processors 1354 described herein.

[0086] This article also covers methods for laser welding, and Figure 14This is a flowchart illustrating an example method for fiber laser bonding to a substrate. At operation 1402, an optical fiber is positioned relative to the substrate, wherein a coating is disposed between the optical fiber and the substrate. The optical fiber may be configured such that a first end of the optical fiber is positioned close to the surface of the substrate, wherein the coating is disposed between the optical fiber and the substrate. In some embodiments, the coating may be an inorganic thin coating or a metallic coating having a thickness of, for example, less than 100 nanometers, and the coating may be configured to absorb photon energy at the wavelength of the laser with an absorptivity of at least 30%. In some embodiments, the coating may include a metallic coating, such as stainless steel or copper. The coating may be configured to become transparent at the wavelength of the laser after the laser is activated. In some embodiments, the substrate may have a material with a melting temperature lower than that of silica. In some embodiments, the substrate may include molten silica. In some embodiments, the optical fiber may be positioned relative to the substrate such that the principal axis of the optical fiber at its first end is orthogonal to the surface of the substrate.

[0087] At operation 1404, a laser is positioned relative to an optical fiber or substrate. In some embodiments, the laser may be positioned close to the second end of the optical fiber, wherein the second end of the optical fiber is positioned away from the substrate. In this case, the laser can emit photon energy to the coating by emitting photon energy from the laser to the second end of the optical fiber such that the photon energy is transferred from the second end of the optical fiber, through the optical fiber, exiting from the first end of the optical fiber, and reaching the coating on the substrate. In other embodiments, the laser may be positioned close to the first end of the optical fiber and close to the substrate, wherein the laser is configured to emit photon energy through the substrate and such that the photon energy can be emitted to the coating. In some embodiments, the laser may be an ultraviolet laser, and the laser may be configured to generate photon energy in pulses. In some embodiments, these pulses may last for 10 nanoseconds or less.

[0088] At operation 1406, a power meter is positioned relative to the optical fiber or substrate. In some embodiments, the power meter may be positioned close to the laser, and a coupler may be used to couple the power meter and the laser to the optical fiber. However, in other embodiments, the laser may be positioned close to a first end of the optical fiber and the power meter may be positioned close to a second end of the optical fiber, or the laser may be positioned close to a second end of the optical fiber and the power meter may be positioned close to a first end of the optical fiber. The power meter may be configured to monitor the amount of photon energy extending through the optical fiber. As noted herein, in some embodiments, a power meter may not be included. In some embodiments using a power meter, a second laser may be provided, wherein this second laser is configured to emit low-power photon energy that can be reflected back to the power meter. Additionally, in some embodiments using a power meter, the power meter may be used only to determine an appropriate amount of photon energy required for the first optical fiber, and the method may be performed by emitting only the determined amount of photon energy for each subsequent optical fiber.

[0089] At operation 1408, one or more optical elements may be provided such that the one or more optical elements guide photon energy from one or more lasers to an optical fiber or substrate. The one or more optical elements may include mirrors, lenses, or light shields, but other optical elements may also be used.

[0090] At operation 1410, the laser emits photon energy through the optical fiber and / or substrate. The emission of photon energy through the optical fiber and substrate enables fiber laser bonding to the substrate. The photon energy can be emitted within the optical path, and there may be no epoxy resin or organic adhesive present within the optical path. By eliminating epoxy resin from the optical path, back reflection signals are minimized, degradation over time is reduced, and environmental stability is improved.

[0091] Method 1400 is merely exemplary and can be modified in various ways. For example, in other embodiments, the order of operations within method 1400 may be changed, and in some embodiments, some of the operations may be performed simultaneously. Additionally, in some embodiments, some operations of method 1400 may be omitted. For example, in some embodiments, operation 1408 may be omitted. In some embodiments, additional operations may also be added to method 1400.

[0092] in conclusion

[0093] 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 set forth herein. Therefore, it should be understood that the embodiments are not limited to the specific embodiments disclosed, and that 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 alternative embodiments may provide different combinations of elements and / or functions 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 covered within the scope of the invention. While specific terminology is used herein, such terminology is used only in a general and descriptive sense and is not intended for limiting purposes.

Claims

1. A method for laser bonding fiber to a substrate, the method comprising: An optical fiber is disposed relative to a substrate such that a first end of the optical fiber is positioned close to the surface of the substrate, wherein a coating is disposed between the optical fiber and the substrate; A laser is positioned relative to the optical fiber or the substrate; as well as The laser emits photon energy through the optical fiber or through the substrate. The emission of photon energy through the optical fiber or through the substrate causes the optical fiber laser to weld to the substrate.

2. The method according to claim 1, wherein the laser is an ultraviolet laser.

3. The method according to claim 1 or claim 2, wherein the emission of photon energy causes the coating to dissolve into the substrate and become transparent at the wavelength of the laser.

4. The method according to any one of claims 1 to 3, wherein the laser is configured to generate photon energy in the form of pulses lasting about 10 nanoseconds or less.

5. The method according to any one of claims 1 to 4, wherein the optical fiber has a second end, wherein the laser is positioned close to the second end of the optical fiber, and wherein causing the laser to emit photon energy through the optical fiber or through the substrate is performed by emitting photon energy from the laser to the second end of the optical fiber.

6. The method according to any one of claims 1 to 5, wherein the laser is positioned close to the substrate, and wherein causing the laser to emit photon energy through the optical fiber or through the substrate is performed by emitting photon energy from the laser through the substrate such that the photon energy then propagates from the substrate to the first end of the optical fiber.

7. The method according to any one of claims 1 to 6, further comprising: A power meter is used to monitor whether the laser welding has been completed.

8. The method of claim 7, further comprising: The second laser is configured to emit feedback photon energy. The feedback photon energy is directed toward the coating such that at least a portion of the feedback photon energy is redirected to the power meter.

9. The method according to any one of claims 1 to 8, further comprising: At least one optical element is provided such that the at least one optical element receives photon energy from the laser and directs the photon energy toward the optical fiber or the substrate.

10. The method of claim 9, wherein the at least one optical element comprises at least one of a mirror, a lens, or a light-shielding plate.

11. The method according to any one of claims 1 to 10, wherein the optical fiber is configured to emit light outward from the optical fiber and toward the substrate in an optical path, wherein no epoxy resin or organic adhesive is disposed within the optical path.

12. The method according to any one of claims 1 to 11, wherein the substrate has a material with a melting temperature lower than that of silica.

13. The method according to any one of claims 1 to 12, wherein the coating is an inorganic thin coating having a thickness of less than about 100 nanometers.

14. The method of claim 13, wherein the coating is configured to absorb the photon energy at the wavelength of the laser with an absorption rate of at least about 30%.

15. The method of claim 14, wherein after the laser is activated, the coating becomes transparent at the wavelength of the laser.

16. The method according to any one of claims 1 to 15, wherein the coating is a metallic coating.

17. The method of claim 16, wherein the coating comprises stainless steel or copper.

18. The method according to any one of claims 1 to 17, wherein the optical fiber is disposed relative to the substrate such that the main axis of the optical fiber at the first end is orthogonal to the surface of the substrate.

19. A non-transitory computer-readable medium for bonding fiber lasers to a substrate, the non-transitory computer-readable medium having software instructions stored thereon, the software instructions causing the one or more processors to perform the following operations when executed by one or more processors: An optical fiber is disposed relative to a substrate such that a first end of the optical fiber is positioned close to the surface of the substrate, wherein a coating is disposed between the optical fiber and the substrate; A laser is positioned relative to the optical fiber or the substrate; as well as The laser emits photon energy through the optical fiber or through the substrate. The emission of photon energy through the optical fiber or through the substrate causes the optical fiber laser to weld to the substrate.

20. The temporary computer-readable medium of claim 19, wherein the coating is an inorganic thin metal coating having a thickness of less than about 100 nanometers.

21. A system for laser bonding of fiber optic cables to a substrate, the system comprising: An optical fiber with a first end; A substrate with a defined surface; coating; A laser configured to emit photon energy; One or more processors; as well as A memory containing computer-readable code configured to cause the one or more processors to perform the following operations when executed: The optical fiber is disposed relative to the substrate such that the first end of the optical fiber is disposed close to the surface of the substrate, wherein the coating is disposed between the optical fiber and the substrate; The laser is positioned relative to the optical fiber or the substrate; as well as The laser emits photon energy through the optical fiber or through the substrate. The emission of photon energy through the optical fiber or through the substrate causes the optical fiber laser to weld to the substrate.

22. The system of claim 21, wherein the laser is an ultraviolet laser configured to generate photon energy in pulses.

23. The system of claim 21 or 22, wherein the coating is an inorganic thin metal coating having a thickness of less than about 100 nanometers.

24. The system of claim 21 or 22, wherein the optical fiber is configured to emit light outward from the optical fiber and toward the substrate in an optical path, and wherein no epoxy resin or organic adhesive is disposed within the optical path.

25. An optical fiber assembly fabricated by the following process: An optical fiber is disposed relative to a substrate such that a first end of the optical fiber is positioned close to the surface of the substrate, wherein a coating is disposed between the optical fiber and the substrate; A laser is positioned relative to the optical fiber or the substrate; as well as The laser emits photon energy through the optical fiber or through the substrate. The emission of photon energy through the optical fiber or through the substrate causes the optical fiber laser to weld to the substrate.

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