Material processing using turbo burst ultrafast laser pulses

Abstract

This provides a method for scribing transparent materials with a laser. [Solution] The method includes performing relative movement between a laser and a transparent material 1.3, pulsing the laser at a first pulse repetition rate in the kHz range to establish the speed of scribing the transparent material 1.3, and forming each of the first laser pulses with a series of second laser pulses having a second pulse repetition rate in the MHz range, wherein each of the second laser pulses is formed from a series of third laser pulses having a third pulse repetition rate in the GHz range.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the laser scribing industry. More particularly, the embodiments described herein provide systems and methods for scribing transparent materials by combining GHz and MHz bursts with short-duration laser pulses.

Background Art

[0002] Glass has been a very strategic material since modern civilization was formed. From construction to automotive and aerospace, from microelectronics to semiconductors, glass is an important player across many industries. Glass continues to be an essential material for many applications, but precise laser scribing is required for success.

[0003] Laser scribing of glass has remained problematic for decades. Generally, previous methods have tried to create the sharpest possible V-shaped surface ablation to cut glass pieces. Such methods were slow and tended to result in larger kerf widths and crack formation along the ablation lines. Another method developed later utilized a CO2 laser heating configuration and a cooling nozzle. This method produced a cut with little or no debris and was excellent for straight cuts but was not suitable for cutting curved lines.

[0004] Another method, known as stealth dicing, involves precisely focusing a laser pulse to create optical destruction within the bulk of the glass material. This creates voids within the glass sample that cause permanent damage. Cutting thicker materials such as glass requires multiple scans to create internal damage across multiple layers. However, the surface roughness resulting from the amount of plasma required for optical destruction within the glass material is not industrially appealing. Therefore, improved systems and methods for laser scribing of glass are needed in this art. [Overview of the project]

[0005] In some embodiments, a method is provided for scribing a transparent material with a laser. The method includes making relative motion between the laser and the transparent material. A first set of laser pulses is pulsed at a first pulse repetition rate in the kHz range to establish the speed of scribing the transparent material. Each of the first laser pulses is formed by a series of second laser pulses having a second pulse repetition rate in the MHz range. Each of the second laser pulses is formed by a series of third laser pulses having a third pulse repetition rate in the GHz range.

[0006] In some embodiments, methods are provided for scribing transparent materials with a laser. The methods include making relative movement between the laser and the transparent material and pulsing the laser at an ultrafast pulse rate in the GHz range, with pulse intervals between picoseconds.

[0007] In some embodiments, a method is provided for scribing a transparent material with a laser. The method includes making relative movement between the laser and the transparent material, and pulse the laser at an ultrafast pulse rate in the GHz range, with picosecond intervals between pulses, such that pulse bursts in subsequent bursts can annihilate previous pulse bursts in the transparent material and create free electrons through ionization.

[0008] In some embodiments, a system for scribing transparent materials is provided. The system includes an ultrafast laser and a lens barrel positioned across the transparent material, the ultrafast laser being pulsed to form a focused region on the transparent material based on optical destruction in air.

[0009] A more detailed description of the disclosure, which is briefly summarized above, can be obtained by referring to embodiments shown in the accompanying drawings, in a manner that allows for a more detailed understanding of the features listed above. However, it should be noted that the accompanying drawings illustrate exemplary embodiments only and should not be considered to limit the scope of the invention, and other equally valid embodiments are permitted. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows a schematic design of a laser scribing system according to several embodiments. [Figure 2] This is a schematic diagram of a laser pulse train generated by turbo burst, according to several embodiments. [Figure 3] This figure shows a method for creating a focus based on optical destruction, according to several embodiments. [Figure 4] This figure shows a method for creating a focus using a diffractive optical element, according to several embodiments. [Figure 5] This figure shows a method for creating a focus using an axicon element, according to several embodiments. [Figure 6] These are schematic diagrams showing the top and edge views of glass material after scribing using turbo burst ultrafast pulses prior to cleavage, according to several embodiments. [Figure 7] These are schematic small views of glass materials after scribing and cleaving according to several embodiments. [Figure 8]This is a schematic diagram of roughness measurement after scribing using conventional burst ultrafast pulses, according to several embodiments. [Figure 9] This is a schematic small view of roughness measurement after scribing using turbo burst ultrafast pulses, according to several embodiments. [Modes for carrying out the invention]

[0011] For ease of understanding, the same reference numerals have been used to indicate identical elements common to the figures where possible. It is intended that elements and features of one embodiment can be usefully incorporated into other embodiments without further detail.

[0012] Embodiments described herein provide systems and methods for scribing transparent materials by combining GHz and MHz bursts with short-duration laser pulses. One embodiment of the system includes an ultrafast laser and a lens barrel positioned across a transparent material, the ultrafast laser being pulsed to form a focused region on the transparent material based on optical destruction in air. In one exemplary embodiment, the laser is focused at a position coinciding with the exit surface of the transparent material.

[0013] The ultrafast lasers described herein are lasers capable of generating ultrashort wave pulses with picosecond durations. The optical disruption described herein is a photoionization process that causes the laser intensity to reach a level above the ionization threshold. This phenomenon occurs when an ultrafast laser is focused in a transparent material, creating a plasma through photoionization. In some embodiments, during the photoionization process, once the density of free electrons passes a critical clamp intensity value, the laser pulse energy is sufficiently absorbed by the transparent material, and the amount of plasma produced begins to increase with increasing pulse energy. In various examples, the clamp intensity value is approximately 1020 W / cm³.

[0014] In some embodiments, the lens barrel includes an optical combination which may include a combination of lenses, a diffractive optical combination, or an axicon optical element. A first set of laser pulses is pulsed at a first repetition rate in the kHz range to establish the speed of scribing of a transparent material. Each of the first laser pulses is formed by a series of second laser pulses having a second pulse repetition rate in the MHz range. Each of the second laser pulses is formed by a series of third laser pulses having a third pulse repetition rate in the GHz range.

[0015] In some embodiments, the first laser repetition rate is between 1 kHz and 100 kHz. The second pulse repetition rate is between 30 MHz and 80 MHz. The interval between the second laser pulses is within the picosecond range.

[0016] In general, there are two distinct methods of interaction with intense laser pulses: laser filamentation and optical destruction. A laser beam tightly focused within a transparent medium forms a localized, high-density plasma around a geometric focus, resulting in optical destruction. The plasma generation mechanism is based on the multiphoton excitation of the initial electron, followed by inverse bremsstrahlung radiation, shock ionization, and electron avalanche processes. Such processes highlight refractive index and void formation processes and form the basis for most short-pulse laser applications in material processing, such as ablation. Conventional optical destruction methods using laser pulses for fragmentation, dicing, scribing, cleaving, cutting, and faceting of transparent materials have drawbacks such as slow processing speed, crack formation and contamination by ablation fragments, and large kerf (groove) widths.

[0017] In contrast, laser filamentation methods offer a new direction for internal laser processing of transparent materials, avoiding ablation or surface damage, dramatically reducing kerf width, preventing crack formation, and accelerating processing times in such scribing applications. Furthermore, high repetition rate lasers define a new direction for enhancing the formation of laser beam filaments with thermal accumulation and other transient responses in the material at a timescale faster than thermal diffusion from the focal volume.

[0018] Various embodiments presented herein utilize short-duration laser pulses (e.g., <100 ps) to generate localized damage zones of less than 1 micron within transparent materials or media. Ultrafast lasers avoid high-density plasma generation, such as optical destruction on the upper surface of transparent media targets, which can easily occur under the demanding optical focusing conditions typically applied and used in femtosecond laser processing. When the optical destruction method is used in combination with ultrafast MHz-GHz laser pulses and the laser focus is adjusted to the exit surface of the target material, ablation fragments and cracks are avoided when the material is unified.

[0019] This process is tuned by a first combination of ultrafast MHz-GHz laser pulses focused to produce optical destruction in air with no target. The location of the optical destruction is adjusted to overlap with the target's exit plane. As soon as the ultrafast laser beam enters the top surface of the target, a nonlinear Kerr effect occurs. The laser's self-focusing mechanism naturally focuses the beam to approximately less than 200 nm, covering the top to bottom of the target. The nonlinear Kerr effect creates an extended focal volume of laser interaction that far exceeds the conventional depth of focus, overcoming optical diffraction that would normally cause the beam to diverge from a small self-focused beam waist.

[0020] In one non-limiting manifestation at such a high repetition rate, the time between laser pulses (e.g., 10 to 200 ns) for heat diffusion to remove the absorbed laser energy is not sufficient, so heat accumulates locally with each laser pulse. In this way, the temperature of the interaction volume rises during subsequent laser pulses, resulting in more efficient heating and laser interaction with fewer thermal cycles. In this region, brittle materials become more ductile, reducing crack formation, and local smooth melting occurs in the elongated void zone.

[0021] In some embodiments, bursts of ultra-fast pulses at approximately 400 picosecond intervals (2.5 GHz) are used. By using GHz burst ultra-fast pulses to interact with transparent materials such as glass, extremely fast input pulses and multi-photon ionization that occurs faster compared to MHz bursting are brought about. Generally, multi-photon ionization of electrons in a material occurs on a time scale of about 10 femtoseconds. Electron-electron interactions occur in less than 100 femtoseconds. Free electrons interact with phonons on a time scale of 1 picosecond. Furthermore, phonon-phonon interactions occur on a time scale of 100 picoseconds. The lifetime of free electrons is on the order of a few nanoseconds. This clearly shows that it is important to impact the material in 400 picosecond steps. Before the free electrons generated by the first pulse of the burst can annihilate the last pulse of the burst, the last pulse has already reached the target and created more free electrons through ionization. These ultra-fast time scales of phonon-phonon interactions generate efficient pulse energies that lead to the generation of very local plasmas that result in the formation of melting on the nanometer scale. By moving the target of the transparent material under the ultra-fast laser beam, different scribing paths can be created. The melting zone creates a weak bond within the laser propagation path that can be used as internal scribing.

[0022] In another embodiment, to deposit additional pulse energy inside a transparent material, a burst of pulses within the MHz range is used with a pulse-to-pulse interval of approximately 15 ns. Each pulse in this burst consists of about 2 to 10 pulses with an interval of about 400 ps. Note that the ultrafast laser pulses at three different repetition rates. The first and fundamental repetition rate of the laser is set at approximately 100 kHz. This affects the scribing speed. For example, if the scribing speed is set at 250 mm / s and the laser repetition rate is set at 100 kHz, the laser pulses will hit the target every 2.5 microns. The second repetition rate is the MHz burst rate. Note that commercial lasers typically have a seeder of 40 to 80 MHz, that is, the pulse-to-pulse interval is in the range of 12.5 ns to 25 ns. The third repetition rate is the GHz burst repetition rate. An ultrafast laser equipped with a regenerative amplifier can be set to generate such high-frequency bursts. In some embodiments, the range is from about 1 to 10 GHz, for example, 2.5 GHz with a pulse-to-pulse interval of 400 ps.

[0023] The systems and methods described herein are applicable to any transparent medium including assemblies of glass, crystal, ceramic, polymer, liquid-encapsulated devices, multilayer materials or devices, and composite materials. It should be further understood that the transparency generally described in this disclosure is not limited to the visible spectrum, but represents any material that is also transparent to laser wavelengths in the vacuum ultraviolet, ultraviolet, visible, near infrared, or infrared spectra.

[0024] The above has provided a rather broad overview of the more appropriate and important features of this disclosure, so that the following detailed explanation can be better understood, and as a result, the contribution to the art can be more fully appreciated. It should be understood by those skilled in the art that the disclosed concepts and particular embodiments can be readily used as a basis for modifying or designing other structures to achieve the same objectives of this disclosure. It should also be understood by those skilled in the art that such equivalent structures do not deviate from the spirit and scope of this disclosure as expressed in the appended claims.

[0025] Figure 1 shows a schematic design of a laser scribing system according to several embodiments. A short-duration turboburst laser pulse 1.1 is focused using a lens barrel 1.2 inside a transparent material or plate 1.3. With an appropriate laser pulse energy, an elongated focused region 1.4 is formed. This region covers from the bottom surface of the transparent material to the top surface of the plate 1.3 and is known as the interaction zone. For example, to scrib a 1 mm thick glass, the interaction zone has a width of less than 200 nm and a height of 1 mm along the scribe line. The properties of the glass are modified in this region by the generation of a strong plasma, making the glass easier to cleave. Cleavage can occur naturally for thermally or chemically strengthened glass, but some glasses, such as soda-lime, can be cleaved by mechanical bending or heat generated by a flame or CO2 laser beam.

[0026] Figure 2 is a schematic diagram of a turbo burst laser pulse train according to several embodiments. The laser pulse train 20 has three different laser repetition rates. The first repetition rate is the standard laser repetition rate. This rate affects the scribing speed. In some embodiments, ultrafast lasers with repetition rates from 1 kHz to 100 kHz may be used. Setting the interaction step to 2.5 microns, 1 kHz is equivalent to a scribing speed of 2.5 mm / sec, and 100 kHz is equivalent to a scribing speed of 250 mm / sec. A scribing speed of 250 mm / sec is particularly useful for line scribing or scribing of larger sizes overall, while slower speeds are suitable for scribing of smaller shapes. The laser repetition rate can generally be set to 100 kHz. A motion stage encoder integrated with the laser generates a gate signal for capturing pulses. For example, when the scribing speed is set to 100 mm / sec, the gate signal captures one laser pulse and ignores the next. To create spline shapes such as smart glass lenses, the motion at the corners is slowed down, the encoder reads the position, and generates a laser-fire signal known as the position-synchronous output, or PSO signal. In this way, the pulses do not overlap at the corners but remain at the same set distance. In the example above, when the speed is reduced to 50 mm / sec at the corners, one laser pulse is automatically captured and the next four pulses are ignored.

[0027] The second repetition rate is the laser seeder rate. This generally varies from 30 MHz to 80 MHz depending on the laser manufacturer. As shown in Figure 2 as an example, this repetition rate can be set to 60 MHz using three pulses in a burst with a pulse interval of 15 ns. Recently, some lasers can be set to operate in a third repetition rate mode, enabling GHz bursting within a regenerative amplifier. As shown in Figure 2, four pulses are set at 400 picosecond intervals (2.5 GHz) for a burst of ultrafast pulses. Using ultrafast pulses of GHz bursts to interact with transparent materials such as glass results in extremely fast input pulses and multiphoton ionization that occurs faster compared to MHz bursting.

[0028] While different laser burst pulse configurations can be tested, here only MHz bursts are used, followed by GHz burst pulses, with each test performed using one to ten pulses within each burst. Combinations of both MHz and GHz pulses can also be used to improve scribing results. The MHz-GHz burst combination is generally referred to as a turbo burst pulse in this specification.

[0029] The present method for turbo burst repetition rates at a 60 MHz second-order repetition rate and a 2.5 GHz third-order repetition rate at a 100 kHz laser frequency is effective for glass with pulse durations ranging from 250 fs to 10 ps. While the 250 fs pulse is only partially converted, the pulse can be chirpened to a longer pulse duration by varying the compressor grating with the laser output. Without even losing generality, the chirpened pulses are also suitable for scribing, just like the converted-limited pulses. This disclosure requires sufficiently high intensity to drive Kerr lens self-focusing in most transparent media, thereby causing plasma generation within transparent materials. Therefore, laser pulse durations in the range of 50 femtoseconds to 25 ps are considered to be within the practical processing range of this disclosure. Other laser pulse durations can also be used without departing from the scope of this disclosure.

[0030] Based on the example pulse train in Figure 2, if the laser has an average power of 40W and is set to a primary repetition rate of 100kHz, each pulse will have 400μJ. When turbo bursts are used with four burst pulses at a secondary repetition rate and five burst pulses at a tertiary repetition rate, the pulse energy is distributed as follows: dividing 400μJ by 4 gives 100μJ per MHz burst, and dividing 100 by 5 gives 20μJ per pulse. It can be assumed that all pulses have substantially equivalent energy per pulse. The pulses can be shaped as ramp-up or ramp-down bursts. For a pulse duration of 200 femtoseconds, the pulse peak power can be calculated as 20μJ / 200fs = 100MW, which is sufficient to create a plasma interaction zone within a glass or other medium.

[0031] Figure 3 shows a schematic diagram of a focusing optical system that precisely focuses a laser beam to cause optical destruction in air without any target. The location of optical destruction is adjusted to overlap with the exit plane of the target. As soon as the laser beam enters the target, a nonlinear Kerr effect occurs. The self-focusing mechanism naturally focuses the beam to less than 200 nm, covering the top to bottom of the target.

[0032] It should be noted that lens combinations that improve spherical aberration are also just examples. Slightly different lens combinations can be used to induce spherical aberration in the beam. While the central ray focuses deep within the material, the peripheral rays focus closer to the lens. The lens combination induces spherical aberration in the beam, thereby increasing the depth of focus.

[0033] In another embodiment of the present disclosure shown in Figure 4, a laser beam 4.1 is focused using a diffractive optical element (DOE) 4.2 to produce multiple focal points 4.3 to 4.5 at approximately the same time. The number and position of the focal points are designed to produce multiple focal points along the focusing line. Without loss of generality, the laser beam may be a Gaussian beam or a flat top-shaped beam before entering the DOE.

[0034] Figure 5 presents another focusing scheme. The laser beam 5.1 is focused using an axicon 5.2. The axicon 5.2 creates a Bessel beam, which also results in a longer focal depth 5.3.

[0035] Overall, in all three focusing methods described above, the laser spot size on the target surface is approximately 100 to 200 microns. The depth of focus can be extended by several millimeters if a laser pulse with a peak power lower than the critical power is used. By using such a beam, no nonlinear effects occur, and the beam will be focused according to linear optical laws. It is difficult to focus a beam to 1 micron while having a depth of focus of several millimeters using such an optical system. To focus a beam with a wavelength of 1 micron to a spot size of 1 micron, an objective lens with an NA of 1 can be used. Such an objective lens (i.e., a 100x objective) will have a depth of focus of several microns. Although a stationary beam can be precisely focused, it is understood that at the target's exit surface, nonlinear effects will correct the focus to be very narrow, for example, with a width of about 200 nm and a length of as much as 2 mm. If a longer depth of field is required, one option is to use a lens with a very low numerical aperture (NA) (e.g., NA of 0.2 to 0.4), but the spot size will be larger.

[0036] It should be noted that self-focusing begins when the laser pulse power exceeds the critical power. As soon as the peak power exceeds the critical power, a pulse with a spot size of 200 microns will contract to a spot size of 1 micron.

[0037] The propagation of ultrafast pulses (e.g., peak power > approximately 5 MW) in transparent optical media is complex due to the strong reshaping of the laser pulse's spatial and temporal profiles through a combination of linear and nonlinear effects, including group velocity dispersion (GVD), linear diffraction, self-phase modulation (SPM), self-focusing, multiphoton / tunnel ionization (MPI / TI) of electrons from the valence band to the conduction band, plasma defocusing, and self-steeping.

[0038] Under any focusing conditions shown in Figures 3 to 5, when a beam is focused within a Kerr material such as glass, the central pulse, which has a much higher intensity than the surrounding area, is converted to a larger refractive index. This causes the pulse center to slow down and the periphery to speed up, resulting in pulse collapse. This phenomenon is known as nonlinear self-focusing. In the focused region, due to the very high peak intensity, multiphoton ionization, field ionization, and electron impact ionization of the medium begin, creating a low-density plasma within the high-intensity portion of the laser beam. The total time required to deposit all GHz burst pulse energy into the material using the burst configuration in Figure 2 is approximately 3 × 400 ps = 1.2 ns. Freely generated electrons have a lifetime of several nanoseconds and plasma shielding, during which time no laser pulses are emitted. For this physical reason, the pulse energy bypasses the plasma shield. Compared to using MHz bursts, the number of pulses in MHz bursts increases, so pulses that arrive later will experience the plasma shielding effect. This plasma temporarily reduces the refractive index at the center of the beam path, thereby causing the beam to defocus and resolve the plasma channel (filament). No effect of using this GHz bursting is observed, and the plasma channel is very smooth and uniform.

[0039] Here, on the timescale of phonon-phonon interaction, the first GHz burst pulse heats the material, while the second set of GHz burst pulses reaches the target (e.g., after about 15 ns), thereby creating new ionization and plasma channel formation. Based on the example pulse train in Figure 2, the same location may be struck five times by 4 GHz pulses each time. Instead of focusing a single 400 μJ pulse on the target, which leads to surface ablation and microcrack formation inside the brittle material, the pulse can be divided into 20 subpulses arranged on a well-ordered timescale. If all pulses are designed to be deposited on a GHz timescale, only up to eight pulses are needed for effective filamentation, with the remainder potentially blocked by the plasma shield generated by the initial pulses.

[0040] If only MHz burst pulses are deposited (i.e., four pulses within a burst), assuming an average power of 40W, 100μJ is radiated to the material each time. This still produces a fine filament, but due to the high peak power, the glass surface roughness remains at approximately 1 micron. In the case of the turbo burst pulses of this disclosure, the surface roughness drops to 120nm. This results in a considerably smoother cut bevel quality.

[0041] Figure 6 is a perspective view of a 1 mm glass sample with a scribing line. Figure 6 shows the surface scribing line and a side view. The sample is cut open by small mechanical force.

[0042] Figure 7 compares the top surface edge roughness when conventional MHz burst ultrafast pulse filamentation (right image) or turbo burst ultrafast pulse (left image) is used. The edges of the sample using conventional filamentation are rougher compared to the turbo burst process. The difference between peaks and troughs reaches several microns, although it is less than 5 microns. While using turbo burst, the edge roughness drops to less than 300 nm.

[0043] Because the peak power of the MHz burst at the laser entrance where filament formation begins is higher (compared to the turbo burst), the glass surface can achieve a very fine ablation effect. Microscopic examination of the edges allows observation of a dent effect at the sample edges, as shown in the right image. Note that this dent effect is not observed when the turbo burst of this disclosure is used (left image).

[0044] Figure 8 shows surface Sa measurements of a small facet of a dissected sample using conventional MHz burst filamentation. Figure 8 shows an average Sa of 680 nm.

[0045] Figure 9 shows the facet of a cut sample scribed by turboburst pulses. After measuring the surface Sa roughness with a Keyence digital microscope, it is clear that a remarkable improvement is achieved compared to conventional filamentation, which has a surface roughness of 140 nm. Thus, the system and method provided herein enables scribing of transparent materials by turbo pulses, thereby significantly reducing surface roughness and resulting in a much smoother cut facet quality. In some high-quality glasses such as fused silica or quartz, turboburst achieves a Sa of approximately 80 nm. This means that the four bending strength values ​​improve by at least 25% to 50%.

[0046] As described above in this specification, this disclosure applies a mixture of GHz and MHz ultrafast laser pulses (turbo bursts) focused at the exit surface inside the Kerr material. The pulses thus generate plasma-modified regions (filaments) via nonlinear effects defined as turbo burst process filaments. The modification dynamics of the focal volume are dramatically enhanced through a combination of transient effects, including one or more of the following: thermal accumulation, transient and permanent nanomelting, color centers, stress, and material defects accumulating in the pulse train, thereby modifying a series of inter-pulse interactions. Laser scribing formed by such turbo burst trains offers considerable advantages in reducing the energy threshold for modified zone formation and increasing zone depth while this zone width is reduced. This phenomenon results in near-zero Kerr width, no fragmentation, and much higher bending strength values. The turbo filamentation burst laser process improves the quality of the cut-out sample edge and fine surface roughness compared to the use of standard filamentation processes.

[0047] The foregoing applies to embodiments of the present disclosure, but other embodiments and further embodiments of the present disclosure can be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the following claims.

Claims

1. A method for scribing transparent materials with a laser, The steps include: performing relative movement between the laser and the transparent material; To establish the scribing speed of the transparent material, the laser is pulsed at a first pulse repetition rate in the kHz range. The steps include forming each of the first laser pulses with a series of second laser pulses having a second pulse repetition rate in the MHz range, A method wherein each of the second laser pulses is formed from a series of third laser pulses having a third pulse repetition rate in the GHz range.

2. The method according to claim 1, wherein focusing the laser involves pulsing the laser through a lens combination that causes optical destruction in air.

3. The method according to claim 1, wherein the pulse output of the laser is performed by passing the laser through a lens combination that induces spherical aberration in the laser beam resulting in a long depth of field.

4. The method according to claim 1, wherein the pulse output of the laser includes passing the laser through a diffractive optical combination that produces a long depth of field.

5. The method according to claim 1, wherein the pulse output of the laser includes passing the laser through an axicon optical element that produces a long depth of field.

6. The method according to claim 1, wherein pulse outputting the laser at a first pulse repetition rate in the kHz range includes pulse outputting the laser at a first pulse repetition rate between 1 kHz and 100 kHz.

7. The method according to claim 1, wherein forming each of the first laser pulses is a series of second laser pulses having a second pulse repetition rate in the MHz range, and further comprising forming each of the first laser pulses with a series of second laser pulses having a second pulse repetition rate between 30 MHz and 80 MHz.

8. The method according to claim 1, wherein forming each of the first laser pulses with a series of second laser pulses includes spacing each of the second laser pulses so that there is a nanosecond interval between them.

9. The method according to claim 1, wherein forming each of the first laser pulses with a series of third laser pulses is performed using a third pulse repetition rate in the range of 1 to 10 GHz.

10. The method according to claim 8, wherein spacing out each of the second laser pulses includes spacing out each of the third laser pulses so that they have a picosecond interval.

11. A method for scribing transparent materials with a laser, Relative movement between the laser and the transparent material, A method comprising pulse outputting the laser at an ultrafast pulse rate where the interval between pulses is a picosecond interval.

12. A method for scribing transparent materials with a laser, Relative movement between the laser and the transparent material, A method comprising: pulse-outputting the laser at an ultrafast pulse rate in the GHz range, with picosecond intervals between pulses, such that a pulse burst in the next burst can annihilate a previous pulse burst in the transparent material and create free electrons through ionization.

13. A system for scribing transparent materials, Ultrafast lasers and, Includes a lens barrel arranged across the transparent material, A system in which the ultrafast laser is pulsed to form a focused region on the transparent material based on optical destruction in air.

14. The system according to claim 13, wherein the ultrafast laser pulses at three different repetition rates, the first repetition rate being in the kHz range, the second repetition rate being in the MHz range, and the third repetition rate being in the GHz range.

15. The system according to claim 13, wherein the lens barrel includes an optical combination comprising one of a lens combination, a diffractive optical combination, or an axicon optical element.

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