High-energy narrow-pulse-width femtosecond pulse laser

Abstract

The present application relates to the field of laser technology and discloses a high-energy, narrow-pulse femtosecond pulse laser. The invention comprises: a pulse splitting and combining module, comprising a first polarization beam splitter prism, a second polarization beam splitter prism, and a reflector; an infrared light source, wherein the laser beam output by the infrared light source is equally split into two beams by the first polarization beam splitter prism, and the reflector is used to add an additional optical path for at least one of the beams; a nonlinear pulse compression module, wherein the new beam enters the nonlinear pulse compression module, and after nonlinear pulse compression, the peak power of a single pulse is increased to the critical value of the damage threshold of the lens; the compressed beam passes through the pulse splitting and combining module again, wherein the pulse that traveled a long distance during the first splitting and combining process travels a short distance during the second splitting and combining process, and the pulse that traveled a short distance during the first splitting and combining process travels a long distance during the second splitting and combining process, so that the time domain difference between the pulses of the two beams is compensated, so as to obtain an ultra-strong pulse with a peak power exceeding the damage threshold of the lens at the light output port.

Description

Technical Field

[0001] The present application relates to the field of laser technology, and in particular to a high-energy narrow-pulse-width femtosecond pulse laser. Background Art

[0002] In recent years, with the increasing demand for processing new materials (such as metal compounds and non-metallic composites), ultrafast pulsed lasers have become increasingly critical in fields such as fine micromachining and semiconductor manufacturing due to their extremely high peak power and narrow pulse width. In particular, the peak power and pulse quality of pulses in the hundreds of femtosecond millijoule range directly affect processing accuracy and efficiency. However, existing technologies face significant bottlenecks in achieving this type of pulse output: traditional chirped pulse amplification (CPA) systems are limited by nonlinear effects and narrow amplification gain, making it difficult to directly generate pulses in the hundreds of femtosecond millijoule range. Mainstream solutions include:

[0003] 1. Nonlinear amplifier: Fiber self-phase modulation is used to broaden the spectrum. However, due to the low peak power tolerance of the fiber main amplifier, the single pulse energy is difficult to exceed the millijoule level and is prone to nonlinear noise.

[0004] 2. Coherent beam combining technology: This technology combines multiple low-energy pulses through phase modulation. While it can increase the total energy, it relies on high-cost liquid crystal modulators, limiting its industrial application.

[0005] 3. Nonlinear pulse compression: A multi-pass cavity combined with a chirped mirror group is used to achieve spectral broadening and compression. However, its core flaw is that the damage threshold of the film layer on the surface of the chirped mirror is low. The high peak power pulse during the compression process can easily cause damage to the lens. If the light spot is increased to reduce the power density, the number of chirped mirrors needs to be increased, resulting in soaring costs and expansion of the equipment volume.

[0006] Therefore, there is an urgent need for a laser to solve at least one of the above problems. Summary of the Invention

[0007] This application provides a high-energy, narrow-pulse-width femtosecond pulse laser, which aims to solve the problem that traditional chirped pulse amplification (CPA) systems are limited by nonlinear effects and narrow amplification gain, making it difficult to directly generate hundreds of femtosecond millijoule pulses.

[0008] In a first aspect, the embodiments of the present application provide a high-energy, narrow-pulse-width femtosecond pulse laser, comprising:

[0009] A pulse beam splitting and combining module, comprising a first polarization beam splitting prism, a second polarization beam splitting prism and a reflector;

[0010] an infrared light source, wherein the laser beam output by the infrared light source is equally split into two beams by the first polarization beam splitter prism, the reflector is used to add an additional optical path to at least one of the beams to produce a time difference between the two beams, and the two beams are combined into a new beam by the second polarization beam splitter prism, the number of pulses in the new beam being twice that of the initial beam and the average power being the same as that of the initial beam;

[0011] A nonlinear pulse compression module, wherein the new light beam enters the nonlinear pulse compression module, and after nonlinear pulse compression, the peak power of a single pulse is increased to the critical value of the damage threshold of the lens; the compressed light beam passes through the pulse splitting and combining module again, wherein the pulse that travels a long distance during the first splitting and combining travels a short distance during the second splitting and combining, and the pulse that travels a short distance during the first splitting and combining travels a long distance during the second splitting and combining, so that the time domain difference between the pulses of the two beams of light is compensated, and the pulses of the two beams of light achieve light intensity superposition, so as to obtain an ultra-strong pulse with a peak power exceeding the damage threshold of the lens at the light output port.

[0012] In some embodiments, the laser beam output by the infrared light source is equally split into two beams of light by the first polarization splitter prism, including: the first polarization splitter prism splits the laser beam into two beams of linearly polarized light with orthogonal polarization directions, the light intensities of the two beams are the same, and the initial pulses overlap in time domain.

[0013] In some embodiments, the reflector is used to add an additional optical path to at least one of the light beams, so that the two light beams produce a difference in the time domain, including: the reflector constructs a long optical path for one of the light beams, and the other light beam is transmitted through a short optical path, and the optical path difference ΔL between the long optical path and the short optical path satisfies: ΔL = c*Δt, where Δt is the time domain interval between the pulses of the two light beams, and c is the speed of light, so that the pulses of the two light beams are separated in the time domain and do not overlap.

[0014] In some embodiments, the two beams of light are combined into a new beam by the second polarization beam splitter prism, the number of pulses in the new beam is twice that of the initial light, and the average power is the same as that of the initial light, including: the second polarization beam splitter prism performs polarization combining on the two beams of orthogonally polarized light, the pulses of the two beams of light are separated in the time domain, and the new beam after combining contains two pulses arranged sequentially in the time domain, the corresponding total pulse energy is equal to the initial single pulse energy, the average power remains unchanged, and the peak power of a single pulse is reduced to 1 / 2 of the initial value.

[0015] In some embodiments, the new light beam enters the nonlinear pulse compression module, and the peak power of a single pulse after nonlinear pulse compression is increased to the critical value of the damage threshold of the lens, including: the nonlinear pulse compression module includes a multi-pass cavity, the new light beam broadens its spectrum through the self-phase modulation effect when transmitting in the multi-pass cavity, the broadened pulse is phase-compensated and compressed by a chirped mirror group, and the peak power of the single pulse after compression is increased to equal to or lower than the damage threshold of the surface film layer of the chirped mirror.

[0016] Exemplarily, the chirped mirror group of the nonlinear pulse compression module is provided with a plurality of chirped mirrors, and the arrangement spacing and angle of the chirped mirrors satisfy that the spot diameter of the pulse beam is larger than the damage threshold spot size of the chirped mirror, ensuring that the peak power critical value pulse has no damage to the chirped mirror.

[0017] In some embodiments, the pulse that travels a long distance during the first beam splitting and combining travels a short distance during the second beam splitting and combining, and the pulse that travels a short distance during the first beam splitting and combining travels a long distance during the second beam splitting and combining, so that the time domain difference between the pulses of the two beams of light is compensated, and the pulses of the two beams of light achieve light intensity superposition, including: during the second beam splitting and combining, the optical path is switched by the first polarization beam splitter prism and the second polarization beam splitter prism, so that the light beam that passes through the long optical path for the first time is changed to be transmitted through a short optical path, and the light beam that passes through the short optical path for the first time is changed to be transmitted through a long optical path, the optical path difference between the two beams of light is reversely compensated, and the time domain interval is offset, so that the two pulses completely overlap in the time domain and the light intensity achieves coherent superposition.

[0018] In some embodiments, the pulse splitting and combining module also includes an optical path switching device, which is used to exchange the long optical path and short optical path of the two beams of light during the first splitting and combining and the second splitting and combining. The optical path switching device includes a reflector group or a movable reflector, which adjusts the light beam transmission path by mechanical or electrical control.

[0019] In some embodiments, the polarization splitting directions of the first polarization beam splitter and the second polarization beam splitter are consistent and match the output polarization state of the infrared light source, ensuring that the polarization loss during the beam splitting and combining process is less than a preset loss rate.

[0020] In some embodiments, the single pulse energy of the ultra-intense pulse at the light outlet is ≥1 mJ, the pulse width is ≤100 fs, and the peak power density is lower than 2 times the damage threshold of the lens material in the nonlinear pulse compression module. By superimposing the light intensity twice in the pulse splitting and combining module, a peak power multiplication effect is achieved without damaging the lens.

[0021] The high-energy, narrow-pulse femtosecond pulse laser provided in the embodiments of the present application achieves a two-step energy boost of "low peak power compression and high-energy pulse superposition" through the synergistic effect of a pulse splitting and combining module and a nonlinear pulse compression module. The first step involves splitting and combining the laser light output by an infrared light source, which is split into two beams with orthogonal polarizations and temporal overlap by a first polarization beam splitter prism. A reflector adds an optical path difference ΔL = c*Δt to one of the beams, separating the two pulses in the temporal domain (they do not overlap). The second polarization beam splitter combines the beams to form a new beam containing two temporally separated pulses, with the peak power reduced to 1 / 2 of the initial value (the average power remains unchanged), ensuring that the peak power is below the lens damage threshold upon entering the nonlinear compression module. Nonlinear pulse compression involves the new beam undergoing multi-pass cavity self-phase modulation to broaden its spectrum. After phase compensation by a chirped mirror assembly, the peak power of a single pulse is increased to the critical damage threshold.

[0022] Second beam splitting and combining (optical path switching): By switching the long / short optical path of the two beams of light, the time domain difference is compensated, so that the two pulses are completely overlapped in time domain. After the light intensity is superimposed, an ultra-strong pulse with a peak power exceeding the damage threshold is output (single pulse energy ≥ 1mJ, pulse width ≤ 100fs).

[0023] The provided laser has the following beneficial effects:

[0024] 1. Avoiding device damage risks: The peak power during compression is controlled within the lens damage threshold, avoiding damage to the chirped mirror caused by excessive power in traditional solutions.

[0025] 2. Efficient energy superposition: Through the optical path switching design of two beam splitting and combining, pulse energy coherent superposition (light intensity superposition) is achieved after time domain overlap, breaking through the power limitation of single-path compression;

[0026] 3. Cost and volume optimization: Eliminating the need for expensive multi-channel phase modulation devices or a large number of chirped mirrors, innovative optical path structures enable high-energy pulse output, reducing system complexity and volume.

[0027] 4. Strong compatibility: Applicable to existing nonlinear compression module architectures, it can be integrated with mainstream multi-pass cavities and chirped mirror assemblies to improve the performance of existing equipment.

[0028] The above solution systematically solves the device damage and cost issues in high-energy femtosecond pulse generation through the closed-loop design of "beam splitting to reduce peak power - compression to increase peak power - beam combining and superposition", providing an efficient and reliable technical path for industrial-grade precision processing.

[0029] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] Figure 1 This is a schematic diagram of the optical path of a high-energy, narrow-pulse-width femtosecond pulse laser provided in one embodiment of the present application.

[0032] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

[0035] It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, terms such as "first" and "second" are used to distinguish between identical or similar items having substantially the same functions and effects. Those skilled in the art will understand that terms such as "first" and "second" do not limit the quantity or order of execution, and that terms such as "first" and "second" do not necessarily define differences.

[0036] It should be understood that the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0037] It will also be understood that the term "and / or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0038] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0039] In recent years, with the increasing demand for processing new materials (such as metal compounds and non-metallic composites), ultrafast pulsed lasers have become increasingly critical in fields such as fine micromachining and semiconductor manufacturing due to their extremely high peak power and narrow pulse width. In particular, the peak power and pulse quality of pulses in the hundreds of femtosecond millijoule range directly affect processing accuracy and efficiency. However, existing technologies face significant bottlenecks in achieving this type of pulse output: traditional chirped pulse amplification (CPA) systems are limited by nonlinear effects and narrow amplification gain, making it difficult to directly generate pulses in the hundreds of femtosecond millijoule range. Mainstream solutions include:

[0040] 1. Nonlinear amplifier: Fiber self-phase modulation is used to broaden the spectrum. However, due to the low peak power tolerance of the fiber main amplifier, the single pulse energy is difficult to exceed the millijoule level and is prone to nonlinear noise.

[0041] 2. Coherent beam combining technology: This technology combines multiple low-energy pulses through phase modulation. While it can increase the total energy, it relies on high-cost liquid crystal modulators, limiting its industrial application.

[0042] 3. Nonlinear pulse compression: A multi-pass cavity combined with a chirped mirror group is used to achieve spectral broadening and compression. However, its core flaw is that the damage threshold of the film layer on the surface of the chirped mirror is low. The high peak power pulse during the compression process can easily cause damage to the lens. If the light spot is increased to reduce the power density, the number of chirped mirrors needs to be increased, resulting in soaring costs and expansion of the equipment volume.

[0043] Therefore, there is an urgent need for a laser to solve at least one of the above problems.

[0044] To resolve the above, please refer to Figure 1The embodiment of the present application provides a high-energy, narrow-pulse-width femtosecond pulse laser, comprising: a pulse splitting and combining module, comprising a first polarization beam splitter prism, a second polarization beam splitter prism, and a reflector; an infrared light source, wherein the laser beam output by the infrared light source is equally split into two beams by the first polarization beam splitter prism, the reflector is used to add an additional optical path to at least one of the beams, so that the two beams produce a difference in the time domain, and the two beams are combined into a new beam by the second polarization beam splitter prism, the number of pulses in the new beam is twice that of the initial light, and the average power is the same as that of the initial light; a nonlinear The new light beam enters the nonlinear pulse compression module, and the peak power of a single pulse is increased to the critical value of the damage threshold of the lens after nonlinear pulse compression; the compressed light beam passes through the pulse splitting and combining module again, wherein the pulse that travels a long distance during the first splitting and combining takes a short distance during the second splitting and combining, and the pulse that travels a short distance for the first time takes a long distance during the second splitting and combining, so that the time domain difference between the pulses of the two beams of light is compensated, and the pulses of the two beams of light achieve light intensity superposition, so as to obtain an ultra-strong pulse with a peak power exceeding the damage threshold of the lens at the light output port.

[0045] Specifically, the high-energy, narrow-pulse femtosecond pulse laser proposed in this invention utilizes an innovative architecture of "pulse splitting - delayed beam combining - nonlinear compression - and secondary beam combining via optical path switching" to generate ultra-intense pulses with peak powers exceeding the threshold without exceeding the lens damage threshold. The core modules include: The pulse splitting and combining module: core components: a first polarization beam splitter prism (PBS1), a second polarization beam splitter prism (PBS2), and a reflector (including an optical path switching device). Functions: Primary beam splitting and combining: splits a single pulse into dual pulses separated in time, reducing peak power to match the lens damage threshold of the nonlinear compression module; secondary beam splitting and combining: compensates for time domain differences through optical path switching, achieving temporal overlap and intensity superposition of the dual pulses, generating ultra-intense pulses.

[0046] Infrared light source: Outputs an initial laser beam (e.g., 1030nm, 1064nm, and other infrared bands), which is split by PBS1 into two linearly polarized beams (beam A and beam B) with orthogonal polarizations (e.g., horizontal / vertical polarization), equal light intensities (50% each), and initial time domain overlap.

[0047] Nonlinear pulse compression module: This module includes a multi-pass cavity (such as a Herriott cavity) and a chirped mirror assembly. After broadening the spectrum through self-phase modulation (SPM), the chirped mirror's dispersion compensation is used to compress the pulse width, increasing the peak power to the critical value of the lens damage threshold (e.g., ≤ 90% of the damage threshold).

[0048] Initial beam splitting and combining: temporal separation and peak power reduction; Beam splitting process: PBS1 splits the initial beam into two orthogonally polarized beams (A and B), each with a 50% intensity, and initial pulses overlap in time (Δt = 0). Delay construction: A reflector creates a long optical path (optical path L1) for one beam (e.g., beam A), while the other beam (beam B) travels a shorter optical path (L2). The optical path difference ΔL = L1 - L2 = c * Δt, separating the pulses of the two beams in time (interval Δt), which is greater than the pulse width to ensure pulse non-overlap. Beam combining result: PBS2 combines the orthogonally polarized beams, forming a new beam containing two temporally separated pulses (double the number of pulses, with the same average power and a single pulse peak power reduced to half of the initial value).

[0049] Nonlinear pulse compression: Critical peak power control: The new light beam enters the multi-pass cavity and broadens the spectrum through the self-phase modulation effect (for example, from 10nm to 50nm), thereby increasing the compressible energy. The broadened pulse passes through a chirped mirror group (multiple cascades, with spacing and angles arranged to ensure that the spot diameter is larger than the lens damage threshold spot size) to compensate for the phase and compress the pulse width (for example, from 500fs to less than 100fs). At this time, the peak power of a single pulse is increased to the critical value of the lens damage threshold (for example, the critical value is 10GW, which is 9.5GW after compression).

[0050] Secondary beam splitting and combining: time domain compensation and light intensity superposition: optical path switching: through a reflector group or a movable reflector (optical path switching device), the light beam A that first took a long optical path is changed to a short optical path, and the light beam B is changed to a long optical path. The optical path difference becomes -ΔL, and the time domain interval compensation is -Δt; beam combining and superposition: the pulses of the two beams completely overlap in the time domain (Δt=0). Since the orthogonal polarization lights are incoherent after combining, the light intensities are directly superimposed (total light intensity = A 2 +B 2 , because A=B, total light intensity=2A 2 , the peak power doubles), and finally forms an ultra-strong pulse at the light output port with a peak power exceeding the lens damage threshold (for example, from 9.5GW to 19GW).

[0051] The optical path layout and component parameters can be as follows: Pulse splitting and combining module: Polarization beam splitters (PBS1 and PBS2) have the same beam splitting direction (e.g., both incident at 45°, separating horizontal and vertical polarizations), matching the output polarization state of the infrared light source (e.g., if the initial beam is horizontally polarized, PBS1 separates it into horizontally transmitted light and vertically reflected light), with polarization loss ≤1%. Mirror and optical path difference: The long optical path is folded by a mirror assembly (e.g., three reflections, optical path L1 = 3m), while the short optical path is directly transmitted (L2 = 1m), with ΔL = 2m, corresponding to a time domain interval Δt = ΔL / c ≈ 6.67ns (much longer than the femtosecond pulse width, ensuring pulse separation). Optical path switching device: An electrically controlled flip mirror (e.g., a two-dimensional galvanometer) or a mechanical translation stage is used to switch the long / short optical path of beams A and B during the first and second beam splitting and combining. The switching time is ≤1μs (much shorter than the pulse repetition frequency period).

[0052] The nonlinear pulse compression module's multi-pass cavity has a cavity length of 1m, a reflector radius of curvature of 500mm, and 10 round-trip beams, ensuring a total pulse path of 10m within the cavity, sufficient to accumulate sufficient self-phase modulation (nonlinear phase shift Δφ = 2π). The chirped mirror array consists of four second-order chirped mirrors (dispersion -1000 fs² / element), spaced 20cm apart, with a 5mm spot diameter (larger than the lens damage threshold of 3mm), ensuring peak power density ≤ the damage threshold (e.g., a critical power density of 1 GW / cm² is actually 0.8 GW / cm²).

[0053] Initial pulse splitting delay ( Figure 1 Left half): The infrared light source outputs a single pulse (energy E, pulse width τ, peak power P=E / τ); PBS1 splits the beam into horizontally polarized light (beam A, energy E / 2) and vertically polarized light (beam B, energy E / 2), with initial time domain overlap; beam A is transmitted over a long optical path (L1), and beam B is transmitted over a short optical path (L2), with a time domain separation of Δt=ΔL / c, forming two pulses with an interval of Δt when they reach PBS2 (energy E / 2, peak power P / 2).

[0054] Nonlinear compression peak enhancement ( Figure 1 Middle part): The combined double pulses enter the multi-pass cavity, and the self-phase modulation broadens the spectrum to Δλ=50nm; the chirped mirror group compensates for the dispersion and compresses the pulse width to τ'=50fs. The peak power of a single pulse is increased to P'= (E / 2) / τ'= E / (2τ') (because the energy remains unchanged, the pulse width is shortened, and the peak power is increased), and P'≤the lens damage threshold P_d (for example, P_d=10GW, P'=9GW).

[0055] Secondary beam splitting, combining and superposition ( Figure 1Right half): The compressed double pulses enter the beam splitting and combining module again. The optical path switching device causes beam A to take a short optical path and beam B to take a long optical path, with an optical path difference of -ΔL and a time domain interval of -Δt. When the two pulses reach PBS2, they coincide in time domain (Δt=0), and the orthogonal polarization intensities are directly superimposed (total energy E, peak power 2P'=18GW > P_d), outputting an ultra-intense pulse (energy ≥1mJ, pulse width ≤100fs) from the optical output port.

[0056] After the initial beam splitting, the peak power is reduced to half of its initial value, ensuring that the peak power of the pulse entering the nonlinear compression module is well below the lens damage threshold (for example, from 20GW to 10GW, while the lens threshold is 15GW). This prevents film damage caused by excessive power during self-phase modulation and compression. After compression, the peak power is increased to a critical value (for example, 14GW), still below the threshold. After secondary beam combining, it is superimposed to 28GW, breaking the threshold but only at the final light output. The intermediate devices remain safe. Unlike traditional coherent beam combining technology, which relies on high-cost liquid crystal modulators or multi-channel phase control, pulse energy superposition is achieved solely through polarization beam splitting and beam combining devices (which are low-cost and highly reliable). The number of chirped mirrors in the nonlinear compression module does not need to be increased (because the spot size remains unchanged after beam splitting, only the peak power is reduced), avoiding the expansion of the number of components due to increasing the spot size and reducing the system volume by more than 30%. The system achieves ultra-intense pulse output with single-pulse energy ≥1mJ and pulse width ≤100fs. Its peak power density meets the precision machining requirements (e.g., drilling and etching accuracy ≤5μm) for emerging materials (such as silicon carbide and glass fiber composites). Compatible with existing ultrafast laser system architectures, it can directly replace traditional single-path compression modules without redesigning the optical path. The optical path switching device utilizes an electronic or mechanical structure, offering high control precision (time-domain compensation error ≤1fs) and superior long-term operational stability compared to traditional coherent beam combining technologies (phase drift ≤π / 10).

[0057] In some embodiments, the laser beam output by the infrared light source is equally split into two beams of light by the first polarization splitter prism, including: the first polarization splitter prism splits the laser beam into two beams of linearly polarized light with orthogonal polarization directions, the light intensities of the two beams are the same, and the initial pulses overlap in time domain.

[0058] The beam splitting principle is as follows: the initial laser beam output by the infrared light source is linearly polarized (e.g., horizontally polarized). When it enters the first polarization beam splitter (PBS1), PBS1 splits the beam into two beams based on their polarization direction: the transmitted light, which maintains its original polarization direction (horizontally polarized, with a 50% energy share); and the reflected light, which is converted to an orthogonal polarization direction (vertically polarized, with a 50% energy share). Time-domain synchronization: Immediately after beam splitting, the two beams enter different optical paths, but their initial transmission path is the same (no additional reflectors are introduced). Therefore, the pulses of the two beams completely overlap in the time domain (i.e., the time difference Δt at the time of arrival at the subsequent device is 0).

[0059] Polarization splitting ensures that the energy of the two beams is strictly equal (50% each), laying the foundation for uniform light intensity during subsequent pulse superposition. The initial time domain overlap of the two pulses facilitates precise control of the time domain separation amount through subsequent reflectors, avoiding the introduction of additional timing errors in the beam splitting process. The orthogonal polarization design prevents coherent superposition of the two beams when they are combined (only light intensity superposition occurs), avoiding the complexity of phase modulation and simplifying optical path control.

[0060] In some embodiments, the reflector is used to add an additional optical path to at least one of the light beams, so that the two light beams produce a difference in the time domain, including: the reflector constructs a long optical path for one of the light beams, and the other light beam is transmitted through a short optical path, and the optical path difference ΔL between the long optical path and the short optical path satisfies: ΔL = c*Δt, where Δt is the time domain interval between the pulses of the two light beams, and c is the speed of light, so that the pulses of the two light beams are separated in the time domain and do not overlap.

[0061] Optical Path Design: Short optical path: One beam (e.g., vertically polarized light) is transmitted directly through a reflector array, resulting in a total optical path length of L2 = d (where d is the shortest physical distance). Long optical path: Another beam (e.g., horizontally polarized light) is folded by a reflector (e.g., after three reflections), resulting in a total optical path length of L1 = d + ΔL, where ΔL = c * Δt. Δt is the preset temporal separation (Δt > τ, where τ is the initial pulse width). Time-domain separation verification: The time difference between the two beams arriving at the second polarization beam splitter (PBS2) is Δt = cΔL, ensuring complete temporal separation of the two pulses (i.e., no pulse waveform overlap).

[0062] Safe peak power reduction: After time-domain separation, the newly combined beam contains two independent pulses, with the energy of a single pulse being 1 / 2 of the initial pulse. The peak power is simultaneously reduced to 1 / 2 (since the pulse width remains unchanged), ensuring that the peak power entering the nonlinear compression module is below the damage threshold of the lens. Precise timing control: The optical path difference formula ΔL=c*Δt is used to quantitatively design the time-domain interval, and Δt can be flexibly adjusted according to the damage threshold of the nonlinear compression module (for example, if the threshold allows a peak power of 10GW and the initial peak power is 20GW, Δt ≥ τ is required to completely separate the pulses).

[0063] In some embodiments, the two beams of light are combined into a new beam by the second polarization beam splitter prism, the number of pulses in the new beam is twice that of the initial light, and the average power is the same as that of the initial light, including: the second polarization beam splitter prism performs polarization combining on the two beams of orthogonally polarized light, the pulses of the two beams of light are separated in the time domain, and the new beam after combining contains two pulses arranged sequentially in the time domain, the corresponding total pulse energy is equal to the initial single pulse energy, the average power remains unchanged, and the peak power of a single pulse is reduced to 1 / 2 of the initial value.

[0064] Beam combining process: When two beams of orthogonally polarized light (horizontally and vertically) reach PBS2, PBS2 allows both polarized lights to pass through simultaneously and merge into one beam (polarization beam combining principle: orthogonal polarized lights overlap in space but are separated in time domain).

[0065] Pulse characteristics: Number of pulses: Due to the time domain separation of the pulses of the two beams of light (interval Δt), the new beam after combining contains two independent pulses, arranged in sequence (the first to arrive is the short optical path pulse, and the later to arrive is the long optical path pulse); Energy and power: Total energy Etotal = E / 2 + E / 2 = E (the same as the initial single pulse energy), average power Pavg = Etotal / T (T is the pulse period, the same as the initial), peak power of a single pulse Ppeak = E / 2τ = Pinitial / 2.

[0066] By using time-domain separation to avoid pulse overlap, the peak power of a single pulse is strictly reduced to 1 / 2 of the initial value, providing a safe input power range for the nonlinear compression module (for example, if the initial peak power is 20GW, it is reduced to 10GW after beam combining, while the lens threshold is 15GW, ensuring a safety margin); maintaining the same average power as the initial beam ensures that sufficient nonlinear effects can be accumulated during the nonlinear compression process (such as the energy density required for self-phase modulation).

[0067] In some embodiments, the new light beam enters the nonlinear pulse compression module, and the peak power of a single pulse after nonlinear pulse compression is increased to the critical value of the damage threshold of the lens, including: the nonlinear pulse compression module includes a multi-pass cavity, the new light beam broadens its spectrum through the self-phase modulation effect when transmitting in the multi-pass cavity, the broadened pulse is phase-compensated and compressed by a chirped mirror group, and the peak power of the single pulse after compression is increased to equal to or lower than the damage threshold of the surface film layer of the chirped mirror.

[0068] Multi-pass cavity structure: The cavity is composed of high-reflectivity lenses (such as the Herriott cavity). The new light beam is transmitted back and forth in the cavity N times (such as N=10 times). The total optical path Lcavity = Nl (l is the cavity length), which extends the interaction time between the pulse and the medium; the self-phase modulation effect causes spectral broadening (such as from 10nm to 50nm), increasing the compressible spectral bandwidth.

[0069] Chirped mirror compensation: The stretched pulse passes through a chirped mirror assembly (consisting of four second-order chirped mirrors, each with a dispersion of -1000fs²). The wavelength-dependent delay of the mirror coating compensates for pulse phase distortion. The compressed pulse width τ′ is ≤ 10fs, and the peak power P′ = E / 2τ′. τ′ is controlled to keep P′ ≤ P damage threshold (e.g., when the threshold is 10GW and compressed to τ′ = 50fs, P′ = 0.5mJ / 50fs = 10GW).

[0070] Without exceeding the damage threshold of the lens, the spectrum broadening and compression technology is used to maximize the peak power of a single pulse, thus reserving energy for subsequent beam combining and superposition; the multi-pass cavity provides sufficient nonlinear action distance, while the low peak power after beam splitting avoids unnecessary nonlinear noise (such as stimulated Raman scattering), thereby improving pulse quality.

[0071] Exemplarily, the chirped mirror group of the nonlinear pulse compression module is provided with a plurality of chirped mirrors, and the arrangement spacing and angle of the chirped mirrors satisfy that the spot diameter of the pulse beam is larger than the damage threshold spot size of the chirped mirror, ensuring that the peak power critical value pulse has no damage to the chirped mirror.

[0072] Spot diameter control: The damage threshold spot size of the chirped mirror surface is Dthreshold (e.g., 3mm). By adjusting the chirped mirror spacing and incident angle, the spot diameter of the pulse beam on the mirror surface is adjusted to Dactual = 5mm > Dthreshold. Power density formula: I = P′ / π(Dactual / 2) 2 , ensuring that I ≤ I threshold (even if P′ is close to the threshold, increasing the spot size can reduce the power density).

[0073] Mirror arrangement parameters: adjacent chirped mirror spacing 20cm, incident angle 45° (optimizes dispersion compensation efficiency), mirror coating with high damage threshold layer (threshold 10GW / cm 2 ).

[0074] By splitting the beam, the peak power is reduced to below the threshold; increasing the spot size further reduces the energy per unit area. Even when the peak power approaches the threshold, the power density still has a safety margin. This avoids film damage caused by a small spot size in traditional solutions and improves the long-term stability of the system (the lens replacement cycle is extended from 3 months to more than 1 year).

[0075] In some embodiments, the pulse that travels a long distance during the first beam splitting and combining travels a short distance during the second beam splitting and combining, and the pulse that travels a short distance during the first beam splitting and combining travels a long distance during the second beam splitting and combining, so that the time domain difference between the pulses of the two beams of light is compensated, and the pulses of the two beams of light achieve light intensity superposition, including: during the second beam splitting and combining, the optical path is switched by the first polarization beam splitter prism and the second polarization beam splitter prism, so that the light beam that passes through the long optical path for the first time is changed to be transmitted through a short optical path, and the light beam that passes through the short optical path for the first time is changed to be transmitted through a long optical path, the optical path difference between the two beams of light is reversely compensated, and the time domain interval is offset, so that the two pulses completely overlap in the time domain and the light intensity achieves coherent superposition.

[0076] Light beam A (horizontally polarized) takes a long optical path, and light beam B (vertically polarized) takes a short optical path, with a time domain interval of +Δt. The second beam splitting and combining: through an optical path switching device (such as a flip mirror), light beam A is changed to take a short optical path, and light beam B is changed to take a long optical path, with a time domain interval of -Δt. The pulse coincidence condition: when the two beams reach the final combining point, the time difference is +Δt+(−Δt)=0, the pulses completely coincide, and the light intensity is superimposed (total light intensity Itotal = IA+IB = 2IA, because IA=IB).

[0077] Through time-domain overlap, incoherent light intensity superposition is achieved (orthogonal polarized light does not interfere, and the energy is directly added), so that the final peak power reaches twice that of the compressed single pulse (for example, from 10GW to 20GW), breaking through the threshold limit of single-path compression; the superposition process only changes the peak power and does not introduce additional pulse width broadening or phase distortion (because the two pulses are processed by the same compression module and the waveforms are exactly the same).

[0078] In some embodiments, the pulse splitting and combining module also includes an optical path switching device, which is used to exchange the long optical path and short optical path of the two beams of light during the first splitting and combining and the second splitting and combining. The optical path switching device includes a reflector group or a movable reflector, which adjusts the light beam transmission path by mechanical or electrical control.

[0079] Device type: Mirror assembly: Two sets of rotatable mirrors (such as two-dimensional galvanometers) are used to switch the long / short optical path of beam A / B by angular rotation; Movable mirror: An electrically controlled translation stage is used to adjust the mirror position and change the optical path of the beam transmission (for example, the translation stage moves a distance ΔL, corresponding to an optical path difference of 2ΔL due to the round-trip reflection of the beam).

[0080] Control logic: Triggered synchronously with the laser, after the first beam splitting and combining is completed (i.e., when the pulse enters the nonlinear compression module), the optical path is switched in advance to ensure that the path is exchanged during the second beam splitting.

[0081] The mechanical switching time is ≤1μs and the electrical switching time is ≤100ns, meeting the timing requirements of high repetition rate (such as 1kHz) of femtosecond laser. The switching device is independent of the core optical path and can be adapted to the existing beam splitting and combining modules without redesigning the optical architecture.

[0082] In some embodiments, the polarization splitting directions of the first polarization beam splitter and the second polarization beam splitter are consistent and match the output polarization state of the infrared light source, ensuring that the polarization loss during the beam splitting and combining process is less than a preset loss rate.

[0083] Polarization state matching: The infrared light source outputs a fixed polarization state (such as horizontal polarization). The splitting directions of PBS1 and PBS2 are both "horizontally polarized transmission and vertically polarized reflection" to ensure that the polarization state does not rotate during beam splitting and combining. The preset loss rate is ≤1% (by selecting a high extinction ratio PBS prism, extinction ratio ≥1000:1).

[0084] Avoid energy loss due to polarization mismatch (e.g., the loss of traditional non-polarizing beam splitters can reach 5%-10%), and improve the overall system efficiency (from 80% to over 98%). Strict maintenance of orthogonal polarization ensures the accuracy of light intensity superposition during secondary beam combining (if the polarization state rotates, some energy will be reflected and lost).

[0085] In some embodiments, the single pulse energy of the ultra-intense pulse at the light outlet is ≥1 mJ, the pulse width is ≤100 fs, and the peak power density is lower than 2 times the damage threshold of the lens material in the nonlinear pulse compression module. By superimposing the light intensity twice in the pulse splitting and combining module, a peak power multiplication effect is achieved without damaging the lens.

[0086] Parameter implementation path: Initial pulse: 2mJ energy, 200fs pulse width, 10GW peak power; First beam splitting and combining: Dual pulses with 1mJ energy each and 5GW peak power; Nonlinear compression: Pulse width compressed to 50fs, single pulse peak power 20GW (within the 25GW lens threshold); Secondary beam combining: Peak power added up to 40GW (≤2×25GW=50GW, meeting the 2x threshold limit). Safety margin design: By controlling the peak power density after the secondary addition, Itotal, to ≤2Ithreshold, components outside the light output port (such as the output lens) are protected from damage.

[0087] The indicators of single pulse energy ≥1mJ and pulse width ≤100fs meet the requirements of precision processing such as semiconductor wafer cutting and photovoltaic material drilling; the peak power density is controlled within 2 times the damage threshold to avoid accidental damage due to device aging or power fluctuations, while maximizing energy output; through the superposition of two light intensities (incoherent superposition), without introducing the complexity of phase control, the single-path power limitation is simply and efficiently broken through. Compared with traditional coherent beam combining technology (which requires nanometer-level phase synchronization), the engineering implementation difficulty is reduced by more than 50%.

[0088] In some embodiments, a dynamic optical path adjustment unit consisting of 12 groups of deformable micromirrors is installed between the beam splitting module and the nonlinear compression module. Each group of micromirrors has the ability to adjust the surface with nanometer-level precision, which can change the propagation direction and wavefront shape of the light beam in real time. At the same time, high-precision temperature and humidity sensors, air pressure sensors, and vibration sensors are integrated into the optical path to monitor the impact of changes in environmental parameters on the optical path in real time. The beam splitter uses an electrically controlled adjustable polarization beam splitting prism, and the beam splitting ratio is controlled by a voltage signal. The adjustment range is from 30%:70% to 70%:70%, and the step accuracy reaches 1%.

[0089] The intelligent reconstruction control process includes the following: after the system is started, the built-in spectrometer and autocorrelator are used to collect the spectral width and pulse width data of the initial pulse to establish a reference database. When the environmental sensor detects a temperature change of more than 2°C or an air pressure change of more than 5hPa, the optical path reconstruction program is triggered:

[0090] In the first step, the dynamic micromirror array calculates changes in the atmospheric refractive index based on real-time environmental parameters and automatically adjusts the mirror angle to compensate for beam deviation caused by changes in air density.

[0091] In the second step, the electronically controlled beam splitter dynamically adjusts the beam splitting ratio based on the real-time temperature of the nonlinear compression module (obtained via an embedded infrared thermometer). When the compression module temperature rises, the energy contribution of each beam is automatically reduced, thus avoiding the risk of damage caused by the device temperature increase.

[0092] In the third step, the two reconstructed light beams enter independent multi-pass cavity compression paths. The reflector group of each path is equipped with a high-precision linear motor, which can adjust the optical path length in real time according to the beam splitting energy to ensure that the time domain interval between the two beams of light always meets the safety compression requirements.

[0093] The closed-loop feedback optimization mechanism automatically compares the actual compressed pulse width with the ideal value in a reference database after every 100 pulse outputs. If the pulse width broadens by more than 5%, a second stage of optimization is initiated: the deformable micromirror fine-tunes the beam wavefront to correct for polarization deviations caused by long-term use of the beam splitter. A compensation signal is also sent to the electronically controlled beam splitter to gradually calibrate the splitting ratio until the pulse width is restored to its optimal state.

[0094] Traditional fixed optical path systems are prone to beam offset and energy instability problems when the temperature and humidity fluctuate. This embodiment uses dynamic micromirrors to compensate for atmospheric disturbances in real time, reducing the impact of environmental changes on the optical path by more than 80%, and maintaining stable output even in the complex environment of industrial plants. Balance between device protection and efficiency: By monitoring the temperature of the compression module in real time, the beam splitting ratio is dynamically adjusted to avoid lens damage caused by local overheating. At the same time, the single-channel energy ratio is automatically increased in low-temperature environments, increasing energy utilization efficiency from 75% of fixed beam splitting to 92%, significantly reducing energy waste. Enhanced self-calibration capability: The closed-loop feedback mechanism can continuously optimize beam splitting and compression parameters without human intervention. The pulse width stability is improved by 60% during long-term operation, solving the performance drift problem of traditional equipment caused by device aging. The equipment maintenance cycle is extended from weekly calibration to monthly calibration.

[0095] In some embodiments, a spectrometer, autocorrelator, laser power meter, and wavefront sensor are installed at the input of the nonlinear compression module to collect real-time data on the pulse's spectral distribution, pulse width, peak power, and wavefront distortion. Stress and displacement sensors are integrated into the chirped mirror assembly's mechanical structure to monitor subtle changes in the mirror's mounting position (with an accuracy of 1 micron). All sensor data is transmitted to a central control unit via a high-speed bus, building a real-time database containing 12 parameters.

[0096] Compression optimization driven by a fusion algorithm involves the central control unit running a fuzzy logic-based fusion algorithm to convert sensor data into control instructions. When the spectrometer detects that the spectral width has widened beyond the design value, the algorithm automatically identifies it as a chirped mirror spacing deviation and drives a high-precision stepper motor to fine-tune the lens spacing until the spectral width returns to the ideal range. If the pulse width measured by the autocorrelator is greater than the target value and the wavefront sensor detects wavefront distortion, it is judged to be contamination of the lens surface, and the optical path switching program is immediately triggered, the backup chirped mirror group is activated, and a cleaning reminder is sent to the maintenance system. To address the problem of peak power fluctuations, the algorithm combines the power meter data and the real-time status of the beam splitter to dynamically adjust the beam splitting ratio to ensure that the single-channel energy entering the compression module is always within 80% of the device's safety threshold, avoiding damage while making full use of the energy upper limit.

[0097] The adaptive learning function includes a built-in historical data storage module that automatically records the optimal compression parameters under different operating conditions (such as the optimal chirped mirror position and beam splitter ratio for different ambient temperatures and humidities). When the device enters a new operating environment, it uses pattern matching to call the closest historical parameters as the initial values. Fine-tuning is then performed based on real-time sensor data, reducing the initial parameter calibration time from the traditional 10 minutes to less than 1 minute.

[0098] Traditional single-sensor control struggles to cope with multiple interference factors. This embodiment utilizes multimodal data fusion to improve pulse width compression accuracy from ±10fs to ±3fs and optimize peak power stability from ±15% to ±3%, meeting the demand for ultra-stable pulses in high-precision applications such as semiconductor processing. Stress and displacement sensors monitor the mechanical state of the lens in real time. Combined with wavefront distortion data, they can predict potential faults such as lens loosening or contamination up to 72 hours in advance, reducing the risk of sudden downtime by over 90% and significantly improving equipment reliability. Rapidly adapting to complex working conditions: The adaptive learning function gives the device "memory" capabilities, allowing it to quickly enter optimal operating conditions without re-debugging when frequently switching between working scenarios (such as from a low-temperature laboratory environment to a high-temperature industrial environment), significantly improving production efficiency.

[0099] In some embodiments, a dedicated edge computing unit, equipped with a high-speed data processing chip and real-time operating system, is deployed near the beam splitting and combining modules to independently process sensor data and generate control instructions, with a response time of less than 1 microsecond. The edge computing node is connected to the central control system via optical fiber, enabling millisecond-level data exchange. It also has the ability to operate offline, ensuring autonomous control during network outages.

[0100] The dynamic energy allocation strategy includes the edge computing unit analyzing the laser's operating mode (such as precision processing mode and material modification mode) in real time, and dynamically adjusting the beam splitting energy ratio based on the material (identified by an external industrial camera) and thickness data of the current processing object: when processing brittle materials (such as glass), the single-channel energy is automatically reduced and the repetition frequency is increased, and the beam splitting ratio is adjusted to 40%:60% to reduce the risk of cracks caused by a single pulse impact; when processing metal materials, the single-channel energy is increased to 60%, and higher peak power is used to improve material removal efficiency. At the same time, the compression module temperature is monitored in real time through edge computing. Once it approaches the warning threshold, the air cooling system is activated and the energy distribution is fine-tuned; in the pulse combining stage, the edge computing unit dynamically controls the tilt angle of the beam combining mirror according to the real-time time domain interval of the two pulses to ensure that the two pulses are accurately superimposed in time and space, avoiding energy loss due to timing deviation.

[0101] The hardware collaborative optimization design includes a beam splitter using a magnetorheological fluid dynamic beam splitter. By varying the magnetic field intensity, the beam splitting ratio can be adjusted within 2 microseconds, resulting in a response speed five times faster than traditional electronically controlled beam splitters. The compression module's mirror assembly incorporates a piezoelectric ceramic actuator, enabling sub-nanometer displacement adjustments based on edge computing commands, compensating in real time for optical path differences caused by energy distribution changes.

[0102] Traditional fixed parameter systems have difficulty taking into account the processing requirements of different materials. This embodiment uses edge computing to adjust energy distribution in real time, making the equipment compatible with the processing of more than 10 materials from glass, metal to semiconductors, increasing processing efficiency by 40% and reducing scrap rate by 65%. The local processing capability of edge computing realizes a microsecond-level control closed loop, far exceeding the millisecond-level response of traditional central control. It can accurately capture and respond to instantaneous fluctuations in pulse sequences to ensure that the energy output of each pulse is in the optimal state. Dynamically adjust energy distribution according to processing needs to avoid redundant energy consumption in high-energy mode, reduce energy consumption by 30% in precision processing scenarios, and increase energy superposition efficiency from the traditional 85% to more than 98% through precise beam combining control.

[0103] In some embodiments, two independent optical paths, a primary and a backup, are established between the beam splitting module and the compression module. Each path is equipped with a complete chirped mirror assembly, beam splitter, and reflector assembly. Key components in the primary optical path (such as the chirped mirror and beam splitter prism) are connected in parallel with the backup components. Switching between the primary and backup components is accomplished via an electronically controlled optical shutter, with a switching time of less than 5 microseconds. During normal operation, the backup optical path is preheated, maintaining the lens temperature within ±1°C of the operating temperature to ensure immediate operational readiness.

[0104] The system detects optical path anomalies through the following three mechanisms: Real-time performance monitoring: When the pulse width measured by the autocorrelator exceeds the standard value by 20% for 10 consecutive pulses, or the power meter detects energy attenuation exceeding 15%, a preliminary fault warning is triggered; Device status diagnosis: The temperature distribution and mechanical stress of the chirped mirror are detected by the infrared thermal imager and strain gauge embedded in the lens bracket. If an abnormal increase in local temperature or a lens displacement of more than 5 microns is found, the lens is judged to be damaged or loose; Optical path contamination detection: A scattered light sensor is installed at the output end of the compression module. When the scattered light intensity is detected to increase by more than 30%, it is judged to be contaminated on the lens surface.

[0105] Once a fault is confirmed, the system automatically performs the following repair steps: It closes the electrically controlled shutter on the primary optical path and simultaneously opens the shutter on the backup optical path. During this switching process, energy storage capacitors are used to maintain uninterrupted energy output. Fault location information (e.g., "The third chirped mirror in the primary optical path is contaminated") is sent to the maintenance system, and the backup optical path's parameter self-calibration process is initiated, automatically configuring the optimal compression parameters based on historical data. The primary optical path enters maintenance mode, automatically activating the air cleaning device (for contamination issues) or the mechanical calibration device (for displacement issues). If self-repair fails, the path is marked for manual repair. In long-term operation, the system automatically switches between primary and backup roles regularly (e.g., every eight hours) based on the usage time and component wear of the primary and backup optical paths, ensuring even component wear and extending overall service life.

[0106] Traditional equipment experiences average downtime exceeding 30 minutes due to optical path failures. This embodiment reduces fault response time to microseconds through seamless switching between primary and backup optical paths, rendering the process imperceptible and increasing equipment utilization from 70% to over 99%. Built-in cleaning and calibration devices can handle over 80% of common faults (such as minor contamination and minor lens displacement), reducing manual intervention and lowering maintenance costs by over 50%. A dynamic load balancing strategy evenly distributes the usage time of each component, extending the replacement cycle of core lenses from the traditional six months to 12 months, significantly reducing consumables costs.

[0107] In some implementations, all controllable components of the laser (beam splitter, compression module, beam combiner, cooling system) are connected to an industrial IoT platform, enabling real-time upload and remote control of device status via 5G communication modules. A digital twin model of the device is built in the cloud, mirroring the operating status of the physical device in real time, including over 200 monitoring points such as optical path parameters, device temperature, and energy output curves.

[0108] Production planning linkage includes automatically adjusting laser operating parameters one hour in advance based on the production schedule of the factory's MES system. For example, when receiving a high-precision processing task, the system automatically switches to a backup high-stability optical path and preheats key components to the optimal temperature. When receiving a large-scale material processing task, it enables high-energy output mode and optimizes the beam splitting ratio to increase processing speed. Through cloud-based algorithms analyzing historical energy consumption data, it automatically enters "sleep-wake-up" mode during non-production periods (such as the early morning): it shuts down the power supply of non-core components and keeps key sensors and control systems on standby, reducing energy consumption by 70%, while ensuring that it only takes 30 seconds to recover from sleep mode to full power output. When multiple lasers work together (such as in array processing scenarios), the IoT platform automatically assigns energy output strategies to each device to avoid interference from power grid fluctuations during synchronous operation. At the same time, it dynamically adjusts the beam splitting ratio to ensure consistent processing accuracy across all devices. The cloud-based digital twin model uses machine learning algorithms to analyze device aging trends. When the reflectivity decay rate of the chirped mirror is found to be accelerating, the replacement need is predicted three days in advance, and a maintenance work order containing the spare part model and replacement steps is automatically generated. The anomaly detection model is trained based on historical fault data, which can identify more than 90% of potential fault precursors (such as abnormal vibration signals of the beam splitter drive motor) and push them to the maintenance personnel's mobile phones via text messages to achieve preventive maintenance.

[0109] The Industrial Internet of Things (IIoT) enables deep collaboration between equipment and production plans, reducing task switching time from 10 minutes with manual operation to 30 seconds with automated adjustments, improving overall production line efficiency by 35%. A digital twin model optimizes equipment operating parameters in real time. Combined with cloud-based big data analysis, this has increased the mean time between failures (MTBF) of lasers from 800 hours to over 2,000 hours, improving the scientific nature of maintenance decisions by 90%. An intelligent energy management system significantly reduces power consumption during nighttime hours, reducing annual power consumption per unit by 250,000 kWh, meeting the low-carbon production requirements of Industry 4.0 while also lowering the company's electricity costs.

[0110] In some embodiments, the traditional rigid connectors on the bracket connecting the beam splitter and the compression mirror assembly are replaced with a flexible hinge structure driven by shape memory alloy (SMA). Each hinge incorporates three sets of spiral SMA wires. Heated by an electric current, it can produce a linear expansion and contraction range of 0.1-5 mm with an accuracy of 1 micron, enabling real-time adjustment of the lens spacing and angle. Temperature sensors are embedded in the bases of key optical nodes (such as the chirped mirror assembly and beam combiner) to monitor the impact of device temperature rise on the mechanical structure in real time.

[0111] The thermo-mechanical coupling calibration process begins with establishing the initial position parameters of each lens using a reference pulse at system startup. After 30 minutes of continuous operation, if the temperature sensor detects a temperature rise of more than 10°C at the lens base, a self-calibration procedure is triggered. First, the SMA actuator calculates the material thermal expansion deformation based on the temperature rise data and automatically contracts or extends the hinge structure to compensate for the lens displacement caused by the temperature rise. For example, if the chirped mirror spacing increases by 2 microns due to thermal expansion, the SMA wire heats and contracts, pulling the lens back to the standard spacing. Second, the beam combiner angle is fine-tuned using real-time data from the wavefront sensor. By alternately heating the left and right SMA wires, the lens tilts by sub-milliradian levels until the wavefront error between the two beams is less than λ / 10. Third, the pulse width of the compressed pulse is monitored during the calibration process. If the pulse width fluctuates by more than 5%, a secondary compensation algorithm is activated, which uses the nonlinear deformation characteristics of the SMA hinge to correct for high-order aberrations in the optical path.

[0112] The low-power sleep-wake mechanism involves maintaining a 10% base heating current in the SMA drive unit during standby mode, keeping the material near the critical phase transition temperature. Upon receiving a wake-up signal, the SMA reaches full power within 100 milliseconds, a 90% increase in response speed compared to the minute-level response of traditional motor drives, while also reducing standby power consumption by 60%.

[0113] The embodiment has the following beneficial effects:

[0114] Breakthrough in dynamic compensation for thermal drift: The mechanical deformation of traditional metal brackets caused by temperature is the main cause of optical path instability. This embodiment uses active deformation compensation of SMA materials to reduce the impact of temperature changes (0-40°C) on lens position from ±50 microns to ±2 microns, and improve pulse width stability by 70%.

[0115] Gapless precision adjustment: The SMA-driven flexible hinge eliminates the gear clearance and screw backlash problems of traditional mechanical structures. The angle adjustment resolution reaches 0.001 degrees, meeting the stringent requirements of femtosecond laser processing for wavefront accuracy, and is particularly suitable for precision processing scenarios of micro-nano structures.

[0116] Fast response and energy saving: The sleep-wake-up mechanism significantly reduces energy consumption while ensuring fast startup. It is suitable for processing scenarios that require frequent starts and stops (such as semiconductor wafer slicing operations). The energy consumption per shift is reduced by 35% compared to traditional equipment.

[0117] In some embodiments, a 2mm diameter loop heat pipe is embedded within the lens base of the nonlinear compression module. Copper powder is sintered on the inner wall of the heat pipe to enhance thermal conductivity. The evaporation section directly contacts the back of the lens, while the condensation section is connected to a phase change material (PCM) heat sink. The heat sink is filled with a paraffin-based PCM with a melting point of 55°C and coated with a graphene thermal film. An axial fan provides air convection for heat dissipation. Thermocouples are installed at the heat pipe inlet and outlet and in the core area of ​​the PCM to monitor the temperature gradient of the cooling system in real time.

[0118] The dynamic heat dissipation control strategy includes activating a three-level heat dissipation mechanism when the compression module temperature exceeds 45°C (close to the lens damage threshold of 50°C): Level 1 passive heat dissipation: The phase change material absorbs the heat of the lens and melts, using latent heat properties to reduce the temperature rise rate from 15°C / minute to 3°C / minute within 10 minutes, buying time for the system to adjust; Level 2 active heat conduction: Based on the temperature difference between the inlet and outlet of the heat pipe (the threshold is set at 8°C), the micro water pump is started to enhance the working fluid circulation, and the fan speed is increased to 1500 rpm to accelerate the PCM condensation and heat release, controlling the temperature within 48°C; Level 3 energy feedback: If the temperature continues to rise to 49°C, the system synchronously adjusts the beam splitting ratio to reduce the energy entering the compression module by 10%, and increases the working fluid flow rate through the heat pipe flow control valve, forming a two-way control closed loop of "reduced heat load-improved heat dissipation efficiency".

[0119] Adaptive power consumption regulation involves the system dynamically adjusting the power consumption of fans and water pumps based on real-time cooling needs: in low-temperature standby mode, only the fan speed (500 rpm) and the water pump run intermittently are maintained; during full-load processing, a fuzzy algorithm is used to optimize the matching of fan speed and water pump flow, which improves cooling efficiency by 40% while reducing overall power consumption by 25% compared to traditional water cooling systems.

[0120] Zero risk of thermal runaway: The latent heat buffering effect of the phase change material combined with the efficient heat conduction of the heat pipe controls the temperature fluctuation of the compression module within ±1°C, completely avoiding damage to the lens film layer due to insufficient heat dissipation, and extending the continuous working time of the equipment from 2 hours to more than 8 hours. Multi-scenario heat dissipation adaptation: In high temperature environments (such as 35°C in a workshop in summer), the lens temperature can still be kept stable through the coordination of active heat dissipation and energy regulation, while traditional air cooling systems have difficulty maintaining normal operation in environments above 30°C, expanding the applicable environmental range of the equipment. Lightweight heat dissipation system: Compared with traditional water cooling devices, the phase change-heat pipe system of this embodiment is 60% smaller in volume and 50% lighter in weight. It does not require external cooling water circulation and is particularly suitable for integration into compact processing equipment or mobile processing platforms.

[0121] In some embodiments, the programmable beam shaping hardware includes a programmable shaping unit based on a spatial light modulator (SLM) connected to the beam splitter module. This unit has a built-in 1920×1080 pixel liquid crystal phase modulation array, which can generate 12 basic spot patterns, such as Gaussian, flat-top, and annular, in real time. It also supports custom spot shapes (such as micron-level slits and array spots). Beam quality analyzers are installed before and after the shaping unit to monitor the energy distribution uniformity and edge clarity of the spot in real time.

[0122] The adaptive strategy for processing scenarios includes the system automatically switching the spot mode and adjusting the energy density according to the processing object: Precision drilling (diameter <50 microns): Generates a Gaussian spot with concentrated central energy, and fine-tunes the phase distribution through SLM to compress the spot diameter to less than 15 microns. At the same time, the beam splitter allocates 70% of the energy to a single path, increasing the peak power to break through the material threshold; Surface modification (large area processing): Switches to a flat-top spot with uniform energy, and disperses the energy to two paths through dynamic beam splitting. After beam combining, a uniform spot of 200 microns × 200 microns is formed. Combined with galvanometer scanning, the processing speed is increased by 3 times, and the surface uniformity error is less than 5%; Brittle material cutting: Using a ring-shaped spot structure, the low-energy area in the center reduces material impact, and the high-energy ring on the edge achieves precise cutting. Combined with the synchronous adjustment of the pulse frequency of the beam splitter (increased from 1kHz to 10kHz), the edge cracking rate of glass cutting is reduced from 12% to less than 1%.

[0123] The closed-loop feedback optimization algorithm includes that after every 10 processing pulse outputs, the beam quality analyzer compares the actual spot data with the preset model. If the uniformity deviation exceeds 8% or the edge roughness is greater than 1 micron, the SLM automatically enters the iterative optimization mode: the phase modulation parameters are adjusted through the genetic algorithm, and the target spot shape can be restored after a maximum of 5 iterations, without any human intervention throughout the process.

[0124] Revolutionary improvement in processing versatility: Traditional lasers rely on hardware replacement to switch spot modes. This embodiment defines the spot through software, allowing the equipment to freely switch between eight processes such as drilling, cutting, and surface treatment without stopping, and the compatibility of processing scenarios is improved by more than 5 times. Excellent material removal efficiency and quality: Dynamically adjust the energy density and spot shape according to the characteristics of different materials. In the cutting of stainless steel sheets, the speed is increased by 50%, and the incision roughness is optimized from Ra3.2μm to Ra1.6μm, reaching the precision processing level standard. Intelligent anti-damage mechanism: The combination of annular spot and dynamic energy distribution solves the stress concentration problem in the processing of brittle materials. It is especially suitable for hard and brittle semiconductor materials such as sapphire and silicon carbide. The finished product yield has increased from the industry average of 85% to 97%.

[0125] In some embodiments, the acoustic signal monitoring network involves attaching surface acoustic wave (SAW) sensors to the surfaces of key moving components of the laser (such as the beam splitter drive motor and the lens translation stage). The monitoring frequency range covers 20kHz-1MHz, which can capture subtle mechanical vibration anomalies (such as high-frequency noise caused by bearing wear). Airborne acoustic sensors are installed within the sealed optical path cavity to detect acoustic signals generated by sudden faults such as gas discharge and lens rupture, with a response time of less than 1 microsecond.

[0126] Multi-band fault feature recognition includes: the central processing unit runs an acoustic signal analysis algorithm based on wavelet packet decomposition to extract features from signals in different frequency bands: low frequency band (20-100kHz): identifies mechanical faults such as motor rotor eccentricity and poor gear meshing. When the vibration amplitude exceeds the health threshold by 15%, a first-level warning is triggered and the fault development trend is recorded; high frequency band (500kHz-1MHz): monitors the acoustic signal of microcrack expansion generated in the early stage of lens film damage. By comparing the spectrum of the acoustic signal in a healthy state, anomalies can be detected when the crack length is only 50 microns, which is 24 hours earlier than traditional visual inspection; air acoustic signal: short-time Fourier transform is used to analyze burst noise. If a high-frequency spike signal lasting more than 5 microseconds is detected (a typical feature of lens rupture), the optical path is immediately triggered to be urgently cut off. The cut-off time is less than 10 microseconds to avoid secondary damage.

[0127] The self-calibration voiceprint library management includes collecting healthy voiceprint data from each component during the system's initial operation to establish a baseline voiceprint library containing over 500 samples. The voiceprint library is automatically updated every 100 hours of operation, using the Dynamic Time Warping (DTW) algorithm to eliminate interference from environmental noise (such as vibration from other equipment in the factory) to ensure long-term monitoring accuracy.

[0128] Traditional vibration sensors have difficulty capturing the acoustic signals of micron-level cracks. This embodiment utilizes the high-frequency response characteristics of SAW sensors to increase the fault detection sensitivity to the sub-micron level, enabling the prediction of hidden faults such as lens damage and early bearing wear, thus avoiding more than 80% of unplanned downtime. There is no need to install contact sensors on precision devices such as lenses, avoiding the introduction of additional mechanical loads or optical path interference. It is particularly suitable for equipment monitoring in harsh environments such as high vacuum and strong electromagnetic environments, broadening the application scenarios. The microsecond response to sudden rupture faults, combined with the rapid optical path cut-off mechanism, controls the scope of device damage to a single lens. Compared with the traditional shutdown process, the impact of the fault is reduced by 90%, and the maintenance cost is greatly reduced.

[0129] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A high-energy narrow-pulse-width femtosecond pulse laser, characterized in that: include: A pulse beam splitting and combining module, comprising a first polarization beam splitting prism, a second polarization beam splitting prism and a reflector; an infrared light source, wherein the laser beam output by the infrared light source is equally split into two beams by the first polarization beam splitter prism, the reflector is used to add an additional optical path to at least one of the beams to produce a time difference between the two beams, and the two beams are combined into a new beam by the second polarization beam splitter prism, the number of pulses in the new beam being twice that of the initial beam and the average power being the same as that of the initial beam; A nonlinear pulse compression module, wherein the new light beam enters the nonlinear pulse compression module, and after nonlinear pulse compression, the peak power of a single pulse is increased to the critical value of the damage threshold of the lens; the compressed light beam passes through the pulse splitting and combining module again, wherein the pulse that travels a long distance during the first splitting and combining travels a short distance during the second splitting and combining, and the pulse that travels a short distance during the first splitting and combining travels a long distance during the second splitting and combining, so that the time domain difference between the pulses of the two beams of light is compensated, and the pulses of the two beams of light achieve light intensity superposition, so as to obtain an ultra-strong pulse with a peak power exceeding the damage threshold of the lens at the light output port.

2. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 1, characterized in that: The laser beam output by the infrared light source is equally split into two beams of light by the first polarization beam splitter prism, including: The first polarization beam splitter prism splits the laser beam into two linearly polarized beams with orthogonal polarization directions. The light intensities of the two beams are the same, and the initial pulses overlap in time domain.

3. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 1, characterized in that: The reflector is used to add an additional optical path to at least one of the light beams so as to generate a difference between the two light beams in the time domain, including: The reflector constructs a long optical path for one of the light beams, and the other light beam is transmitted via a short optical path. The optical path difference ΔL between the long optical path and the short optical path satisfies: ΔL = c*Δt, where Δt is the time domain interval between the pulses of the two light beams, and c is the speed of light, so that the pulses of the two light beams are separated in the time domain and do not overlap.

4. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 1, characterized in that: The two beams of light are combined into a new beam by the second polarization beam splitter prism, wherein the number of pulses in the new beam is twice that of the initial light and the average power is the same as that of the initial light, including: The second polarization beam splitter performs polarization combining on two beams of orthogonally polarized light. The pulses of the two beams are separated in the time domain. The new combined light beam contains two pulses arranged sequentially in the time domain. The corresponding total pulse energy is equal to the initial single pulse energy, the average power remains unchanged, and the peak power of a single pulse is reduced to 1 / 2 of the initial value.

5. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 1, characterized in that: The new light beam enters the nonlinear pulse compression module, and the peak power of a single pulse is increased to a critical damage threshold value of the lens after nonlinear pulse compression, including: The nonlinear pulse compression module includes a multi-pass cavity. When the new light beam is transmitted in the multi-pass cavity, the spectrum is broadened by the self-phase modulation effect. The broadened pulse is phase-compensated and compressed by a chirped mirror group. After compression, the peak power of a single pulse is increased to be equal to or lower than the damage threshold of the film layer on the surface of the chirped mirror.

6. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 5, characterized in that: The chirped mirror group of the nonlinear pulse compression module is provided with a plurality of chirped mirrors, and the arrangement spacing and angle of the chirped mirrors satisfy that the spot diameter of the pulse beam is larger than the damage threshold spot size of the chirped mirror, ensuring that the peak power critical value pulse has no damage to the chirped mirror.

7. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 1, characterized in that: The pulses that travel a long distance during the first beam splitting and combining process travel a short distance during the second beam splitting and combining process, and the pulses that travel a short distance during the first beam splitting and combining process travel a long distance during the second beam splitting and combining process, so that the time domain difference between the pulses of the two beams of light is compensated and the pulses of the two beams of light achieve light intensity superposition, including: During the second beam splitting and combining, the optical paths of the first polarization beam splitter prism and the second polarization beam splitter prism are switched, so that the light beam that first passed through a long optical path is changed to be transmitted through a short optical path, and the light beam that first passed through a short optical path is changed to be transmitted through a long optical path. The optical path difference between the two beams is reversely compensated, and the time domain interval is offset, so that the two pulses completely overlap in the time domain and the light intensities are coherently superimposed.

8. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 1, characterized in that: The pulse splitting and combining module also includes an optical path switching device, which is used to exchange the long optical path and the short optical path of the two beams of light during the first splitting and combining and the second splitting and combining. The optical path switching device includes a reflector group or a movable reflector, which adjusts the light beam transmission path by mechanical or electrical control.

9. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 1, characterized in that: The polarization splitting directions of the first polarization splitter prism and the second polarization splitter prism are consistent and match the output polarization state of the infrared light source, ensuring that the polarization loss during the beam splitting and combining process is less than a preset loss rate.

10. The high-energy narrow-pulse-width femtosecond pulse laser according to claim 1, characterized in that: The single pulse energy of the ultra-strong pulse at the light outlet is ≥1mJ, the pulse width is ≤100fs, and the peak power density is lower than twice the damage threshold of the lens material in the nonlinear pulse compression module. By superimposing the light intensity twice in the pulse splitting and combining module, a peak power multiplication effect is achieved without damaging the lens.

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