High power fiber laser array beam tilt aberration detection and correction system

Abstract

The present application relates to the technical fields of high-power fiber laser, and provides a kind of high-power fiber laser array beam tilt aberration detection and correction system, including main laser, tilt aberration correction and collimation module, beam splitter, probe laser, fiber beam splitter, (6+1) fiber combiner, fiber wavelength division multiplexer, adaptive fiber collimator, optical flat, photoelectric detector, control module, using the dual-wavelength design of main laser with wavelength λ1 and probe laser with wavelength λ2, using probe laser with wavelength λ2 to establish and maintain internal parallel reference online, and using this reference to detect the tilt deviation of main laser.The system has simple structure, strong stability, does not need to modify existing fiber laser array, and is more operable.

Description

Technical Field

[0001] This invention relates to the field of fiber laser array technology, and in particular to a high-power fiber laser array beam tilt aberration detection and correction system. Background Technology

[0002] The power and energy of fiber lasers are mainly affected by nonlinear effects, thermal effects, and optical damage, resulting in limited average power and pulse energy output from a single fiber. Therefore, array beam combining technology is considered to obtain higher power output. A necessary condition for array beam combining technology is that the sub-beams are parallel to each other. However, due to assembly errors of optical components and external vibrations, the sub-beams cannot be perfectly parallel. Any angular deviation between sub-beams will lead to far-field spot dispersion and reduced energy concentration, affecting the array beam combining effect.

[0003] To address the aforementioned issues, a technical solution using optical window feedback probe light has been proposed. This solution offers advantages such as a compact system structure and fewer spatial optical components. However, it requires modifications to the internal structure of the fiber laser, such as coupling the probe light into the laser's optical path and adding a circulator. This poses significant challenges for laser arrays constructed directly from pre-made lasers.

[0004] Therefore, there is an urgent need for a new scheme that requires no operation on existing lasers, while also achieving fewer spatial optical elements and better compactness, high precision and stability, and the ability to directly correlate and correct tilt aberrations of each individual beam unit. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this invention proposes a high-power fiber laser array beam tilt aberration detection and correction system. This system is a novel tilt aberration correction system based on a precision optical plane, requiring no operation on existing lasers, while also achieving fewer spatial optical components and better compactness.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-power fiber laser array beam tilt aberration detection and correction system includes:

[0008] The main laser outputs an N-channel sub-laser with a wavelength of λ1.

[0009] The tilt aberration correction and collimation module corrects the tilt aberration of the N-channel laser and collimates the output to the beam splitter. Most of the array beam with high power is reflected by the beam splitter and output, while the remaining small portion of the array beam with low power is transmitted to the optical plate through the beam splitter.

[0010] The optical plate has two optical surfaces. The first optical surface is highly transparent to wavelength λ1, and the second optical surface is highly transparent to wavelength λ1 and highly reflective to wavelength λ2.

[0011] N adaptive fiber collimators, each receiving a laser beam transmitted from an optical plate and collimating the output;

[0012] The bundle-combining arms of N (6+1)×1 fiber optic combiners are each connected to the output of an adaptive fiber optic collimator.

[0013] The probe laser outputs a probe laser with wavelength λ2 to the fiber beam splitter, which divides the probe laser into N paths. The signal arm of each (6+1)×1 fiber combiner is connected to one of the beam splitting arms of the fiber beam splitter.

[0014] N fiber wavelength division multiplexers, each with a (6+1)×1 fiber combiner, one pump arm of which is connected to the first port of a fiber wavelength division multiplexer.

[0015] N first photodetectors are each connected to the second port of an optical fiber wavelength division multiplexer to receive optical signals of wavelength λ1 and convert them into first electrical signals.

[0016] N second photodetectors are each connected to the third port of an optical fiber wavelength division multiplexer to receive optical signals with wavelength λ2 and convert them into second electrical signals.

[0017] The control module is connected to all photodetectors. It controls the optical axis angle of the corresponding adaptive fiber collimator according to the second electrical signal of each channel, so that the N probe sub-lasers are perpendicular to the second optical surface of the optical plate. It controls the tilt aberration correction and collimation module according to the first electrical signal of each channel, and adjusts the optical axis of the N-path laser to make it coincide with the optical axis of the corresponding adaptive fiber collimator.

[0018] The beneficial effects of this invention are:

[0019] This invention provides an array beam tilt aberration detection and correction system based on a precision optical plane. The system adopts a dual-wavelength design with a main laser (λ1) and a probe laser (λ2) separated. The probe laser with wavelength λ2 is used to establish and maintain an internal parallel reference online, and the tilt deviation of the main laser is detected by using this reference. The detection of the main laser is indirectly achieved by the change in its coupling efficiency with the reference optical axis.

[0020] Furthermore, the system employs a distributed N-channel parallel structure, with each channel possessing an independent fiber combiner, wavelength division multiplexer, and photodetector. This enables the control module to simultaneously and independently acquire and process the tilt information of each sub-beam unit (including its probe beam and main laser), and drive the corresponding actuators (adaptive fiber collimator, tilt aberration correction module) for independent and precise correction. This one-to-one unitized control strategy avoids crosstalk between channels, improving the system's correction accuracy, speed, and flexibility.

[0021] Furthermore, by maximizing the reflection signal of each probe laser on the second optical surface of the optical plate, the system forces all probe beams to be perpendicular to the same physical plane (optical plate), thus establishing an internally generated, absolute spatial angular reference for the entire system. This reference is based on fixed optical elements and does not depend on the external environment or far-field targets, therefore exhibiting extremely high stability and resistance to environmental interference.

[0022] In the system's detection optical path (probe optical path), the sub-beams of the adaptive fiber collimator share the same optical path as the sub-beams in the tilt aberration correction and collimation module, which ultimately requires correction. The goal of the correction is to make the main laser optical axis coincide with the optical axis of the already calibrated adaptive fiber collimator.

[0023] The system has a simple structure, high stability, and does not require modification of existing fiber laser arrays, making it more operable. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a high-power fiber laser array beam tilt aberration detection and correction system provided in one embodiment;

[0026] Numbering on the map:

[0027] 1. Main laser; 2. Tilt aberration correction and collimation module; 3. Beam splitter; 4. Probe laser; 5. Fiber beam splitter; 6. (6+1)×1 fiber combiner; 7. Fiber wavelength division multiplexer; 8. Adaptive fiber collimator; 9. Optical plate; 9-1. First optical surface; 9-2. Second optical surface; 10. First photodetector; 11. Second photodetector; 12. Control module. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Reference Figure 1 One embodiment provides a high-power fiber laser array beam tilt aberration detection and correction system, including a main laser 1, a tilt aberration correction and collimation module 2, a beam splitter 3, a probe laser 4, a fiber beam splitter 5, a (6+1)×1 fiber beam combiner 6, a fiber wavelength division multiplexer 7, an adaptive fiber collimator 8, an optical plate 9, a first photodetector 10, a second photodetector 11, and a control module 12.

[0030] Main laser 1 is used to output N sub-lasers with wavelength λ1, where N is greater than 2;

[0031] The tilt aberration correction and collimation module 2 is used to perform tilt aberration correction and collimation on the N-path sub-laser and output the array beam to the beam splitter 3.

[0032] Beam splitter 3 is used to reflect most of the power of the array beam and transmit the remaining small portion of the power of the array beam to the optical plate 9.

[0033] An optical plate 9 is set in the transmission light path of the beam splitter 3. The optical plate 9 has two optical surfaces. The first optical surface 9-1 is highly transparent to wavelength λ1, and the second optical surface 9-2 is highly transparent to wavelength λ1 and highly reflective to wavelength λ2.

[0034] N adaptive fiber collimators 8 are set up one-to-one with N sub-lasers. Each adaptive fiber collimator 8 receives one sub-laser transmitted from the optical plate 9 and collimates and outputs it.

[0035] N (6+1)×1 fiber optic combiners 6, each (6+1)×1 fiber optic combiner 6 has a combiner arm on its first side and 6 pump arms and a signal arm on its second side, and each (6+1)×1 fiber optic combiner 6 has a combiner arm connected to an adaptive fiber optic collimator 8.

[0036] Probe laser 4, used to output probe laser with wavelength λ2;

[0037] The fiber beam splitter 5 is used to evenly divide the probe laser into N probe sub-lasers. The signal arm of each (6+1)×1 fiber combiner 6 is connected to one beam splitting arm of the fiber beam splitter 5 to receive one probe sub-laser.

[0038] N fiber wavelength division multiplexers 7, each with a (6+1)×1 fiber combiner 6, one pump arm of which is connected to the first port of a fiber wavelength division multiplexer 7; each fiber wavelength division multiplexer 7 is used to separate optical signals of wavelength λ1 and wavelength λ2, and output them through the second port and third port of each fiber wavelength division multiplexer 7 respectively.

[0039] N first photodetectors 10, each first photodetector 10 is connected to the second port of a fiber wavelength division multiplexer 7, used to receive the optical signal of wavelength λ1 separated by the fiber wavelength division multiplexer 7 and convert it into a first electrical signal.

[0040] N second photodetectors 11, each second photodetector 11 is connected to the third port of a fiber wavelength division multiplexer 7, used to receive the optical signal with wavelength λ2 separated by the fiber wavelength division multiplexer 7 and convert it into a second electrical signal.

[0041] The control module 12 is connected to all the first photodetectors 10 and the second photodetectors 11. It controls the optical axis angle of the corresponding adaptive fiber collimator 8 according to the second electrical signal of each channel, so that each probe sub-laser is perpendicular to the second optical surface of the optical plate 9. It controls the tilt aberration correction and collimation module 2 according to the first electrical signal of each channel, and adjusts the optical axis of the N sub-lasers to make it coincide with the optical axis of the corresponding adaptive fiber collimator 8.

[0042] Specifically, the main laser 1 outputs N laser beams with a wavelength of λ1, which are then processed by tilt aberration correction and collimation module 2 to form an array beam output. After passing through beam splitter 3, most of the beam is reflected and a small portion is transmitted for tilt aberration detection. The transmitted light passes through optical plate 9 (both sides of the optical plate 9 are coated with high transmittance for wavelength λ1) and is coupled into the corresponding adaptive fiber collimator 8. After passing through the corresponding (6+1)×1 fiber combiner 6 and fiber wavelength division multiplexer 7, the light is finally converted into a first electrical signal by the corresponding first photodetector 10 and output to control module 12.

[0043] The probe laser 4 emits a probe laser with a wavelength of λ2. The probe laser is evenly divided into N probe sub-lasers by the fiber optic beam splitter 5. After passing through the (6+1)×1 fiber optic combiner 6, the sub-lasers are output to the optical plate 9 by the adaptive fiber optic collimator 8. Due to the coating on the second optical surface 9-2 of the optical plate 9, the second optical surface 9-2 of the optical plate 9 has high reflectivity for the λ2 wavelength incident at 0 degrees. Therefore, the N probe sub-lasers return to the adaptive fiber optic collimator 8 after being reflected by the second optical surface 9-2 of the optical plate 9. After passing through the corresponding (6+1)×1 fiber optic combiner 6 and fiber wavelength division multiplexer 7, the sub-lasers are finally converted into a second electrical signal by the corresponding second photodetector 11 and output to the control module 12.

[0044] The probe laser and its optical path design are mainly to correct the tilt aberrations of the adaptive fiber collimator 8 itself. These aberrations are mainly caused by assembly errors, temperature fluctuations, mechanical vibrations, etc.

[0045] The intensity of the second electrical signal output by each second photodetector 11 is a function of the angle between the corresponding probe sub-laser and the second optical surface of the optical plate 9. When the intensity of the second electrical signal reaches its minimum value, the corresponding probe sub-laser is perpendicular to the second optical surface 9-2 of the optical plate 9. The control module 12 performs feedback control on the optical axis angle of the corresponding adaptive fiber collimator 8 based on the intensity of the second electrical signal of each channel, so that each probe sub-laser is perpendicular to the second optical surface 9-2 of the optical plate 9, and the probe sub-lasers remain parallel to each other, thus completing the probe optical path calibration.

[0046] The intensity of the first electrical signal output by each first photodetector 10 is a function of the angle between the optical axis of the corresponding main optical path sub-laser and the optical axis of the corresponding adaptive fiber collimator 8. When the intensity of the first electrical signal reaches its minimum value, the optical axis of the corresponding main optical path sub-laser coincides with the optical axis of the corresponding adaptive fiber collimator 8. When the optical axis of the sub-laser in the main optical path is completely coincident with the optical axis of the corresponding adaptive fiber collimator 8, the corresponding first photodetector 10 will output a minimum value. The control module 12 adjusts the optical axis of the corresponding sub-laser according to the intensity of the first electrical signal of each channel through tilt aberration correction and collimation module 2, so that the optical axis of each sub-laser in the main optical path coincides with the optical axis of the corresponding adaptive fiber collimator 8, thereby achieving parallelism between the sub-lasers.

[0047] The specific process is as follows: First, the adaptive fiber collimator 8 in the probe optical path is adjusted. Since the probe laser of wavelength λ2 is reflected back through the second optical surface 9-2 of the optical plate 9 and returns along the original path, it enters the corresponding second photodetector 11 via the corresponding fiber wavelength division multiplexer 7 and is input to the control module 12. This adjusts the adaptive fiber collimators 8 whose output beam direction is deviated, completing the closed-loop control of the adaptive fiber collimators 8. After the above adjustment, the output beam of the adaptive fiber collimator 8 can be completely perpendicular to the 9-2 surface of the optical plate 9, thereby achieving parallel optical axes of all array beams of the adaptive fiber collimator 8 and completing the self-calibration of the probe optical path. At this time, the optical axis correction of the fiber laser array beam system to be calibrated begins. Similarly, since the lasers of wavelength λ1 enter the corresponding first photodetector 10 via the corresponding fiber wavelength division multiplexer 7 and are input to the control module 12, the direction of the deviated sub-beams is adjusted, completing the closed-loop control of the tilt aberration correction and collimation module 2, keeping the optical axes of the array beams to be calibrated parallel.

[0048] The main laser 1, probe laser 4, fiber wavelength division multiplexer 7, fiber beam splitter 5, (6+1)×1 fiber combiner 6, adaptive fiber collimator 8, first photodetector 10, and second photodetector 11 are all fiber optic or fiber-coupled devices, and are connected to each other by fiber optic fusion splices or patch cords. Electrical signals are transmitted between the control module 12, tilt aberration correction and collimation module 2, adaptive fiber collimator 8, and other devices via wires.

[0049] The main laser 1 is a fiber laser, and its output power and center wavelength λ1 are determined by the user according to the system requirements.

[0050] The tilt aberration correction and collimation module 2 is a structure capable of correcting optical axis tilt aberration in real time. It has the ability to correct tilt aberration of the main laser and the ability to collimate and combine beams. It can be implemented by various technical approaches, including but not limited to spatial light modulators, microelectromechanical system mirror arrays, or adaptive fiber collimator arrays. Alternatively, it can adopt a method such as fiber collimator + fast tilt mirror + spatial beam combining. The specific solution can be selected according to actual needs, including but not limited to the array beam tilt aberration correction system proposed in publication number CN 113985539 A.

[0051] The beam splitter 3 can be a commercially available flat-panel beam splitter 3, whose aperture is larger than the circumcircle diameter of the main laser array beam during operation, enabling high reflectivity and beam splitting of the main laser wavelength. Its splitting ratio must ensure that the transmitted light power meets the response requirements of the first photodetector 10. One side of the beam splitter 3 facing the main laser incident direction is coated with a beam-splitting film, and the other side is coated with an anti-reflection film for the main laser wavelength. The beam-splitting film can withstand the main laser power density.

[0052] The optical plate 9 can be fabricated and coated with high-light-resistant glass or crystal materials such as fused silica. The two sides of the lens are planar, namely its first optical surface 9-1 and second optical surface 9-2. The main laser incident surface is coated with an anti-reflection film for the main laser wavelength λ1. The coatings on opposite surfaces should simultaneously meet the conditions of high reflectivity for the probe laser wavelength λ2 and high transmittance for the main laser wavelength λ1. The second optical surface 9-2 of the optical plate 9 is the reference surface. The surface shape requirements for the first optical surface 9-1 and the second optical surface 9-2 are PV less than λ / 4, RMS less than λ / 20, and λ = 632.8 nm. The first optical surface 9-1 of the optical plate 9 is coated with an anti-reflection film that provides high transmittance for wavelength λ1, and the second optical surface 9-2 of the optical plate 9 is coated with a film that provides high transmittance for wavelength λ1 and high reflectivity for wavelength λ2.

[0053] The probe laser 4 can be a commercial single-mode fiber laser, with a wavelength interval of more than 50nm between its center wavelength λ2 and the main laser wavelength λ1, in order to meet the usage requirements of the fiber wavelength division multiplexer 7, and the output power can meet the detection requirements of the second photodetector 11.

[0054] The fiber beam splitter 5 can be a commercial 1×N polarization-maintaining fiber beam splitter 5. The type of input fiber of the fiber beam splitter 5 matches the type of output fiber of the probe laser 4. The fiber beam splitter 5 can divide the output laser power into N paths, which is the same as the number of beams in the main laser array.

[0055] The (6+1)×1 fiber combiner 6 described in the above embodiments can be a commercial fiber combiner, which includes 6 pump fibers, 1 signal fiber, and 1 double-clad output fiber. The six pump fibers are symmetrically arranged around the signal fiber located at the center, and are fused together with the double-clad output fiber after being fused tapered. The signal of the signal fiber must be matched with the output signal of the fiber splitter 5.

[0056] The adaptive fiber collimator 8 can be a commercially available fiber collimator with tilt aberration correction. This collimator has high transmittance for both wavelengths of the main laser λ1 and the probe laser λ2. The pigtail type of the adaptive fiber collimator 8 is the same as the output double-clad fiber type of the (6+1)×1 fiber combiner 6. The number and arrangement of the units in the adaptive fiber collimator 8 array are the same as those in the main laser array, and they correspond precisely to each other.

[0057] The fiber wavelength division multiplexer 7 can be a commercial fiber wavelength division multiplexer 7, with its input wavelengths being the main laser wavelength λ1 and the probe laser wavelength λ2, respectively. The two input fiber types of the fiber wavelength division multiplexer 7 are matched with the pigtail types of the first photodetector 10 and the second photodetector 11, respectively, and its output fiber type is matched with the pump arm fiber type of the (6+1)×1 fiber combiner 6.

[0058] The first photodetector 10 can be a commercially available fiber-coupled photodetector with a response band covering the main laser wavelength. Its detection sensitivity matches its output optical power, and its pigtail type matches the input fiber type of the fiber wavelength division multiplexer 7. The response bandwidth meets the signal acquisition requirements of the control module 12.

[0059] The second photodetector 11 can be a commercial fiber-coupled photodetector with a response band covering the probe light wavelength, a detection sensitivity that matches the output optical power, a pigtail model that matches the input fiber model of the fiber wavelength division multiplexer 7, and a response bandwidth that meets the signal acquisition requirements of the control module 12.

[0060] The control module 12 can be developed using signal processors such as microcontrollers, FPGAs, and DSPs. It can receive electrical signals from each photodetector and generate corresponding voltage control signals, which are then transmitted to the tilt aberration correction and collimation module 2 and the adaptive fiber collimator 8. The algorithm running on the control module 12 can employ optimization algorithms such as hill climbing. It controls the electrical signals output by each photodetector to preset values, thereby achieving parallelism of the optical axes of all array beams.

[0061] Specifically, the system implements the tilt aberration detection and correction process, including the following steps:

[0062] S1, Probe optical path calibration:

[0063] The probe laser 4 is activated, and the probe laser 4 outputs a probe laser with a wavelength of λ2. This laser is split into N probe sub-lasers by the fiber optic beam splitter 5. The N probe sub-lasers are transmitted to N adaptive fiber collimators 8 through a (6+1)×1 fiber optic combiner 6. The N probe sub-lasers output by the N adaptive fiber collimators 8 are reflected by the second optical surface 9-2 of the optical plate 9 and return along the same path. They are then received by the corresponding second photodetector 11 through the fiber wavelength division multiplexer 7 and converted into a second electrical signal. The control module 12 independently controls the optical axis angle of each adaptive fiber collimator 8 according to the second electrical signal of each channel to optimize the second electrical signal, so that each probe sub-laser is perpendicular to the second optical surface 9-2 of the optical plate 9 and remains parallel to each other. Specifically, the control module 12 independently controls the optical axis angle of each adaptive fiber collimator 8 according to the second electrical signal strength of each channel, so that the second electrical signal strength reaches the optimal value, thereby making each probe sub-laser perpendicular to the second optical surface 9-2 of the optical plate 9, and keeping each probe sub-laser parallel to each other.

[0064] S2, Main optical path calibration;

[0065] After the probe optical path calibration is completed, the main laser 1 is turned on. The probe laser 4 and its subsequent optical paths work simultaneously with the main laser 1 and its subsequent optical paths. The optical path principle of the probe laser is the same as above and will not be repeated. The main laser 1 outputs N sub-lasers with a wavelength of λ1. After passing through the tilt aberration correction and collimation module 2 and the beam splitter 3, the array beam transmitted through the beam splitter 3 is transmitted through the optical plate 9. The N sub-lasers are coupled into the corresponding adaptive fiber collimators 8. The N sub-lasers output from the N adaptive fiber collimators 8 pass through the corresponding (6+1)×1 fiber combiner 6 and fiber wavelength division multiplexer 7, and are received by the corresponding first photodetector 10 and converted into a first electrical signal. The control module 12 controls the tilt aberration correction and collimation module 2 to independently adjust the optical axis of each sub-laser according to the first electrical signal of each channel, so that the optical axis of each laser coincides with the optical axis of the corresponding adaptive fiber collimator 8 that has been calibrated by S1, thereby achieving parallelism between the lasers. Specifically, the control module 12 controls the tilt aberration correction and collimation module 2 to independently adjust the optical axis of each sub-laser according to the first electrical signal strength of each channel, so that the optical axis of each sub-laser coincides with the optical axis of the corresponding, calibrated adaptive fiber collimator 8, thereby achieving parallelism between the sub-lasers.

[0066] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A high-power fiber laser array beam tilt aberration detection and correction system, characterized in that, include: The main laser outputs an N-channel sub-laser with a wavelength of λ1. The tilt aberration correction and collimation module corrects the tilt aberration of the N-channel laser and collimates the output to the beam splitter. Most of the array beam with high power is reflected by the beam splitter and output, while the remaining small portion of the array beam with low power is transmitted to the optical plate through the beam splitter. The optical plate has two optical surfaces. The first optical surface is highly transparent to wavelength λ1, and the second optical surface is highly transparent to wavelength λ1 and highly reflective to wavelength λ2. N adaptive fiber collimators, each receiving a laser beam transmitted from an optical plate and collimating the output; The bundle-combining arms of N (6+1)×1 fiber optic combiners are each connected to the output of an adaptive fiber optic collimator. The probe laser outputs a probe laser with wavelength λ2 to the fiber beam splitter, which divides the probe laser into N paths. The signal arm of each (6+1)×1 fiber combiner is connected to one of the beam splitting arms of the fiber beam splitter. N fiber wavelength division multiplexers, each with a (6+1)×1 fiber combiner, one pump arm of which is connected to the first port of a fiber wavelength division multiplexer. N first photodetectors are each connected to the second port of an optical fiber wavelength division multiplexer to receive optical signals of wavelength λ1 and convert them into first electrical signals. N second photodetectors are each connected to the third port of an optical fiber wavelength division multiplexer to receive optical signals with wavelength λ2 and convert them into second electrical signals. The control module is connected to all photodetectors. It controls the optical axis angle of the corresponding adaptive fiber collimator according to the second electrical signal of each channel, so that the N probe sub-lasers are perpendicular to the second optical surface of the optical plate. It controls the tilt aberration correction and collimation module according to the first electrical signal of each channel, and adjusts the optical axis of the N-path laser to make it coincide with the optical axis of the corresponding adaptive fiber collimator.

2. The high-power fiber laser array beam tilt aberration detection and correction system according to claim 1, characterized in that, The first optical surface of the optical plate is coated with an antireflective film that has high transmittance to wavelength λ1, and the second optical surface of the optical plate is coated with a film layer that has high transmittance to wavelength λ1 and high reflectance to wavelength λ2.

3. The high-power fiber laser array beam tilt aberration detection and correction system according to claim 1, characterized in that, The second optical surface of the optical plate is the reference surface. The surface shape requirements for the first and second optical surfaces are PV less than λ / 4, RMS less than λ / 20, and λ is 632.8nm.

4. The high-power fiber laser array beam tilt aberration detection and correction system according to claim 1, characterized in that, The (6+1)×1 fiber optic combiner has a combining arm on its first side and six pump arms and a signal arm on its second side.

5. The high-power fiber laser array beam tilt aberration detection and correction system according to claim 4, characterized in that, The main laser, probe laser, fiber wavelength division multiplexer, fiber beam splitter, (6+1)×1 fiber combiner, adaptive fiber collimator, and photodetector are all fiber optic or fiber-coupled devices, and the devices are connected by fiber optic fusion splices or jumper heads; the control module, tilt aberration correction and collimation module, and adaptive fiber collimator transmit electrical signals and are connected by wires.

6. The high-power fiber laser array beam tilt aberration detection and correction system according to any one of claims 1 to 5, characterized in that, The tilt aberration correction and collimation module is a structure capable of correcting optical axis tilt aberration in real time, including a spatial light modulator, a microelectromechanical system mirror array, or an adaptive fiber collimator array.

7. The high-power fiber laser array beam tilt aberration detection and correction system according to claim 6, characterized in that, The intensity of the second electrical signal output by the second photodetector is a function of the angle between the probe laser and the second optical surface of the optical plate. The control module performs feedback control on the optical axis angle of the corresponding adaptive fiber collimator according to the intensity of the second electrical signal of each channel, so that each probe laser is perpendicular to the second optical surface of the optical plate and the probe lasers remain parallel to each other.

8. The high-power fiber laser array beam tilt aberration detection and correction system according to claim 1, 2, 3, 4, 5, or 7, characterized in that, The intensity of the first electrical signal output by the first photodetector is a function of the angle between the optical axis of the corresponding sub-laser and the optical axis of the corresponding adaptive fiber collimator. When the optical axis of the sub-laser is completely coincident with the optical axis of the corresponding adaptive fiber collimator, the first photodetector will output a minimum value. The control module adjusts the optical axis of the corresponding sub-laser according to the intensity of the first electrical signal of each channel through tilt aberration correction and collimation module, so that the optical axis of each sub-laser coincides with the optical axis of the corresponding adaptive fiber collimator, thereby realizing that the sub-lasers are parallel to each other.

9. The high-power fiber laser array beam tilt aberration detection and correction system according to any one of claims 1 to 5, wherein the system realizes the tilt aberration detection and correction process by comprising the following steps: S1, Probe optical path calibration: The probe laser is activated, outputting a probe laser with wavelength λ2. This laser is split into N probe sub-lasers by a fiber optic beam splitter. These N probe sub-lasers are then transmitted to N adaptive fiber optic collimators via a (6+1)×1 fiber optic combiner. The N probe sub-lasers output by these collimators are reflected back along the same path by the second optical surface of the optical plate and then pass through the fiber optic wavelength division multiplexer. Finally, they are received by the corresponding second photodetector and converted into a second electrical signal. The control module independently controls the optical axis angle of each adaptive fiber optic collimator based on the second electrical signal of each channel to optimize the second electrical signal, thereby ensuring that each probe sub-laser is perpendicular to the second optical surface of the optical plate and that the probe lasers remain parallel to each other. S2, Main optical path calibration; After the probe optical path calibration is completed, the main laser is turned on. The probe laser and its subsequent optical paths and the main laser and its subsequent optical paths work simultaneously. The main laser outputs N sub-lasers with a wavelength of λ1. After passing through the tilt aberration correction and collimation module and the beam splitter, the array beam transmitted through the beam splitter is transmitted through the optical plate. The N sub-lasers are coupled into the corresponding adaptive fiber collimators. The N sub-lasers output from the N adaptive fiber collimators pass through the corresponding (6+1)×1 fiber combiner and fiber wavelength division multiplexer, and are received by the corresponding first photodetector and converted into the first electrical signal. The control module controls the tilt aberration correction and collimation module to independently adjust the optical axis of each sub-laser according to the first electrical signal of each channel, so that the optical axis of each laser coincides with the optical axis of the corresponding adaptive fiber collimator that has been calibrated by S1, thereby achieving parallelism between the lasers.

10. The high-power fiber laser array beam tilt aberration detection and correction system according to claim 9, in S1, the control module independently controls the optical axis angle of each adaptive fiber collimator according to the second electrical signal intensity of each channel, so that the second electrical signal intensity reaches the optimal value, thereby making each probe sub-laser perpendicular to the second optical surface of the optical plate, and each probe laser remaining parallel to each other; In S2, the control module controls the tilt aberration correction and collimation module to independently adjust the optical axis of each sub-laser according to the first electrical signal strength of each channel, so that the optical axis of each sub-laser coincides with the optical axis of the corresponding, calibrated adaptive fiber collimator, thereby achieving parallelism between the sub-lasers.

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