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

Abstract

The invention relates to the technical field of high-power optical fiber laser, and provides a high-power optical fiber laser array light beam tilt aberration detection and correction system which comprises a main laser, a tilt aberration correction and collimation module, a spectroscope, a probe laser, an optical fiber beam splitter, a (6 + 1) * 1 optical fiber beam combiner, an optical fiber wavelength division multiplexer, a self-adaptive optical fiber collimator and an optical flat plate. The device comprises a photoelectric detector, a control module, a dual-wavelength design of a main laser with a wavelength of lambda1 and a probe laser with a wavelength of lambda2, an internal parallel reference is established and maintained on line by using the probe laser with the wavelength of lambda2, and the inclination deviation of the main laser is detected by using the reference. The system is simple in structure, high in stability and better in operability, and an existing fiber laser array does not need to be modified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber laser array, in particular to a high-power fiber laser array beam tilt aberration detection and correction system. BACKGROUND

[0002] The power and energy of the fiber laser are mainly affected by the nonlinear effect, thermal effect and optical damage, etc., so that the average power and pulse energy output by a single fiber are limited, so the array beam synthesis technology is considered to obtain higher power output. The necessary condition of the array beam synthesis technology is that the sub-beams are parallel to each other, but due to the assembly error of the optical element, the influence of external vibration and other factors, the sub-beams cannot be completely parallel, and the angle deviation between any sub-beams will lead to far-field spot dispersion and energy concentration decrease, affecting the effect of array beam combination.

[0003] In order to solve the above problems, some people have proposed a technical scheme of using optical window to feedback probe light, which has the technical advantages of compact system structure and few spatial optical elements, but needs to modify the internal structure of the fiber laser, such as coupling probe light in the laser light path and adding a circulator, etc. It has great difficulty for the laser array directly using finished laser.

[0004] Therefore, a new scheme is needed, which does not need to operate the existing laser, can realize less spatial optical element and better compactness, can realize high precision and high stability, and can directly associate and correct the tilt aberration of each independent beam unit. SUMMARY

[0005] In view of the above problems existing in the prior art, the present application proposes a high-power fiber laser array beam tilt aberration detection and correction system, which is a new type of tilt aberration correction system taking a precise optical plane as a reference, without any operation on the existing laser, and can realize less spatial optical element and better compactness.

[0006] In order to achieve the above technical purpose, the technical scheme adopted by the present application is as follows: A high-power fiber laser array beam tilt aberration detection and correction system, comprising: N paths of sub-lasers with a main laser output wavelength λ1; A tilt aberration correction and collimation module, which collimates and outputs N paths of sub-lasers after tilt aberration correction to a beam splitter, and most of the power of the array beam is reflected and output by the beam splitter, and the rest of the small power of the array beam is transmitted to an optical flat through the beam splitter; The optical flat has two optical faces, the first optical face is high-transmissive to the wavelength λ1, and the second optical face is high-transmissive to the wavelength λ1 and high-reflective to the wavelength λ2; N adaptive fiber collimators, respectively receiving a sub-laser from the optical flat and collimating output; N (6+1) x 1 fiber combiners are connected to the output end of an adaptive fiber collimator; The probe laser of the probe laser output wavelength λ2 is divided into N paths by the fiber splitter, and each (6+1) x 1 fiber combiner is connected to a beam splitter arm of the fiber splitter. N fiber wavelength division multiplexers, one of the (6+1) x 1 fiber combiners is connected to the first port of one of the fiber wavelength division multiplexers; N first photodetectors are connected to the second port of one of the fiber wavelength division multiplexers, respectively, to receive optical signals of wavelength λ1 and convert them into first electrical signals; N second photodetectors are connected to the third port of one of the fiber wavelength division multiplexers, respectively, to receive optical signals of wavelength λ2 and convert them into second electrical signals; A control module is connected to all photodetectors, and 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 flat; the tilt aberration correction and collimation module is controlled according to the first electrical signal of each channel, and the optical axis of the N sub-lasers is adjusted to coincide with the optical axis of the corresponding adaptive fiber collimator.

[0007] The beneficial effects of the present application are: The present application provides an array beam tilt aberration detection and correction system based on a precise optical plane, which adopts a dual-wavelength design of main laser (λ1) and probe laser (λ2), uses the probe laser of wavelength λ2 to establish and maintain an internal parallel reference online, and detects the tilt deviation of the main laser based on this reference, and the detection of the main laser is indirectly realized through the change of the coupling efficiency between the reference optical axis.

[0008] Further, the system adopts a distributed N-channel parallel structure, each channel has independent fiber combiners, wavelength division multiplexers and photodetectors. This enables the control module to simultaneously and independently acquire and process the tilt information of each sub-beam unit (including its probe light and main laser), and drive the corresponding actuators (adaptive fiber collimator, tilt aberration correction module) to perform independent and accurate correction. This one-to-one unit control strategy avoids cross-talk between channels and improves the correction accuracy, speed and flexibility of the system.

[0009] Further, the system forces all probe beams to be perpendicular to the same physical plane (optical flat) by maximizing the reflected signal of each channel probe laser at the second optical face of the optical flat, and establishes an internal self-generated, absolute spatial angle reference for the whole system. This reference is based on fixed optical elements and is independent of external environment or far-field targets, and thus has extremely high stability and anti-environment interference capability.

[0010] The sub-beams of the adaptive fiber collimator in the detection light path (probe light path) of the system are highly co-coupled with the sub-beams in the tilt aberration correction and collimation module which needs to be finally corrected. The goal of correction is to make the main laser optical axis coincide with the optical axis of the adaptive fiber collimator which has been calibrated.

[0011] The system has simple structure and strong stability, does not need to modify the existing fiber laser array, and is better in operability. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on the drawings shown.

[0013] Figure 1 FIG. 1 is a structural schematic diagram of a high-power fiber laser array beam tilt aberration detection and correction system provided by an embodiment; Reference numerals in the drawings: 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 flat; 9-1, first optical face; 9-2, second optical face; 10, first photodetector; 11, second photodetector; 12, control module. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort fall within the scope of protection of the present application.

[0015] Reference Figure 1In an embodiment, a high-power fiber laser array beam tilt aberration detection and correction system is provided, comprising 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, (6+1) x 1 fiber combiner 6, a fiber wavelength division multiplexer 7, an adaptive fiber collimator 8, an optical flat 9, a first photodetector 10, a second photodetector 11, and a control module 12.

[0016] The main laser 1 is configured to output N sub-lasers of wavelength λ1, where N is greater than 2. The tilt aberration correction and collimation module 2 is configured to correct the tilt aberration and collimate the N sub-lasers, and output an array beam to the beam splitter 3. The beam splitter 3 is configured 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 flat 9. The optical flat 9 is disposed on the transmission light path of the beam splitter 3, and the optical flat 9 has two optical surfaces, a first optical surface 9-1 that is highly transmissive to wavelength λ1, and a second optical surface 9-2 that is highly transmissive to wavelength λ1 and highly reflective to wavelength λ2. N adaptive fiber collimators 8 are disposed one-to-one corresponding to the N sub-lasers, and each adaptive fiber collimator 8 receives a sub-laser transmitted from the optical flat 9 and collimates and outputs the sub-laser. N (6+1) x 1 fiber combiners 6, each (6+1) x 1 fiber combiner 6 has one combiner arm on its first side and six pump arms and one signal arm on its second side, and the combiner arm of each (6+1) x 1 fiber combiner 6 is connected to one adaptive fiber collimator 8. The probe laser 4 is configured to output a probe laser of wavelength λ2. The fiber beam splitter 5 is configured to uniformly divide the probe laser into N probe sub-lasers, and the signal arm of each (6+1) x 1 fiber combiner 6 is connected to one beam splitting arm of the fiber beam splitter 5 to receive one probe sub-laser. N fiber wavelength division multiplexers 7, one of the pump arms of each (6+1) x 1 fiber combiner 6 is connected to a first port of one fiber wavelength division multiplexer 7, and each fiber wavelength division multiplexer 7 is configured to separate optical signals of wavelength λ1 and wavelength λ2 and output them through second and third ports of the fiber wavelength division multiplexer 7, respectively.

[0017] N first photodetectors 10, one first photodetector 10 is connected to the second port of one fiber wavelength division multiplexer 7 to receive the optical signal of wavelength λ1 separated by the fiber wavelength division multiplexer 7 and convert it into a first electrical signal. N second photodetectors 11, one second photodetector 11 corresponds to connect one third port of the fiber wavelength division multiplexer 7, for receiving the wavelength λ2 optical signal separated by the fiber wavelength division multiplexer 7 and converting it into a second electrical signal; The control module 12 is connected with all the first photodetector 10 and the second photodetector 11, according to the second electrical signal of each channel to control the optical axis angle of the corresponding adaptive fiber collimator 8, so that each road probe laser and the second optical surface of the optical flat 9 remain perpendicular; according to the first electrical signal of each channel to control the tilt aberration correction and collimation module 2, adjust the optical axis of N road laser, make it coincide with the optical axis of the corresponding adaptive fiber collimator 8.

[0018] Specifically, the main laser 1 outputs N road laser with wavelength λ1, which forms an array beam output after the tilt aberration correction and collimation module 2, and most of the reflected output after the beam splitter 3, a small part of the transmission is used for tilt aberration detection. The transmitted light is coupled into the corresponding adaptive fiber collimator 8 after passing through the optical flat 9 (both sides of the optical flat 9 are coated with film, which is high transmission to λ1 wavelength), through the corresponding (6+1)×1 fiber combiner 6, fiber wavelength division multiplexer 7, and finally converted into first electrical signal output to the control module 12 by the corresponding first photodetector 10.

[0019] The probe laser 4 emits probe laser with wavelength λ2, which is uniformly divided into N road probe laser by the fiber beam splitter 5, and is output to the optical flat 9 by the adaptive fiber collimator 8 after the (6+1)×1 fiber combiner 6. Because the second optical surface 9-2 of the optical flat 9 is coated, the second optical surface 9-2 of the optical flat 9 has high reflection to 0 degree incident λ2 wavelength, so the N road probe laser is reflected by the second optical surface 9-2 of the optical flat 9 and returns to the adaptive fiber collimator 8, and finally converted into second electrical signal output to the control module 12 by the corresponding second photodetector 11 through the corresponding (6+1)×1 fiber combiner 6, fiber wavelength division multiplexer 7.

[0020] The design of probe laser and its optical path is mainly to correct the tilt aberration of adaptive fiber collimator 8 itself, which is mainly caused by assembly error, temperature fluctuation, mechanical vibration and other reasons.

[0021] The second electric signal intensity output by each second photodetector 11 is a function of the angle between the corresponding probe sublaser and the second optical surface of the optical flat 9. When the second electric signal intensity reaches a minimum value, the corresponding probe sublaser is perpendicular to the second optical surface 9-2 of the optical flat 9. The control module 12 performs feedback control on the optical axis angle of the corresponding adaptive fiber collimator 8 according to the second electric signal intensity of each channel, so that each probe sublaser is perpendicular to the second optical surface 9-2 of the optical flat 9, and each probe sublaser remains parallel to each other, thereby completing the probe optical path calibration.

[0022] The first electric signal intensity output by each first photodetector 10 is a function of the angle between the corresponding main optical path sublaser optical axis and the optical axis of the corresponding adaptive fiber collimator 8. When the first electric signal intensity reaches a minimum value, the corresponding main optical path sublaser optical axis coincides with the optical axis of the corresponding adaptive fiber collimator 8. When the sublaser optical axis in the main optical path coincides with the optical axis of the corresponding adaptive fiber collimator 8, the corresponding first photodetector 10 outputs a minimum value. The control module 12 adjusts the sublaser optical axis of each channel by the tilt aberration correction and collimation module 2 according to the first electric signal intensity of each channel, so that the sublaser optical axis of each channel in the main optical path coincides with the optical axis of the corresponding adaptive fiber collimator 8, thereby realizing the parallelism between each sublaser.

[0023] The specific process is as follows: First, adjust the adaptive fiber collimator 8 in the probe optical path. Since the λ2 wavelength probe laser is reflected by the second optical surface 9-2 of the optical flat 9 and returns to the original path, it enters the corresponding second photodetector 11 through the corresponding fiber wavelength division multiplexer 7 and is input to the control module 12, so as to adjust each adaptive fiber collimator 8 with a deviation in the output beam direction, thereby completing the closed-loop control of the adaptive fiber collimator 8. The output beam of the adaptive fiber collimator 8 after the above adjustment can be completely perpendicular to the 9-2 surface of the optical flat 9, thereby realizing the parallelism of the optical axes of all array beams of the adaptive fiber collimator 8 and completing the self-correction of the probe optical path. At this time, the optical axis correction of the fiber laser array beam system to be corrected is started. Similarly, since each λ1 wavelength laser enters the corresponding first photodetector 10 through the corresponding fiber wavelength division multiplexer 7 and is input to the control module 12, so as to adjust the direction of the sub-beam with a deviation, thereby completing the closed-loop control of the tilt aberration correction and collimation module 2, and the array beam optical axis to be corrected remains parallel.

[0024] The main laser 1, the probe laser 4, the fiber wavelength division multiplexer 7, the fiber beam splitter 5, the (6+1)×1 fiber combiner 6, the adaptive fiber collimator 8, the first photodetector 10, and the second photodetector 11 are all fiber or fiber coupled devices, and are connected by fiber fusion or jumper head. The control module 12, the tilt aberration correction and collimation module 2, the adaptive fiber collimator 8, and other devices transmit electric signals and are connected by wires.

[0025] The main laser 1 is a fiber laser, and the output power and central wavelength λ1 are determined by the user according to the system requirements.

[0026] The tilt aberration correction and collimation module 2 is a structure capable of correcting the optical axis tilt aberration in real time, has tilt aberration correction capability for the main laser and beam collimation and synthesis capability, and can be realized by various technical approaches, including but not limited to a spatial light modulator, a micro-electro-mechanical system mirror array, or an adaptive fiber collimator 8 array, etc. It can also be realized by a fiber collimator + fast tilt mirror + spatial beam synthesis method, etc. The specific scheme can be selected according to actual requirements, including but not limited to the array beam tilt aberration correction system disclosed in CN 113985539 A.

[0027] The beamsplitter 3 can be a commercial flat beamsplitter 3, which has a larger light passing aperture than the circumscribed circle diameter of the main laser array beam when working, and can highly reflect and split the main laser wavelength, and the splitting ratio needs to ensure that the transmitted optical power meets the response requirements of the first photodetector 10. One side of the beamsplitter 3 is coated with a beamsplitting film, and the other side is coated with a main laser wavelength antireflection film. The beamsplitting film can withstand the main laser power density.

[0028] The optical flat 9 can be developed from strong light resistant glass or crystal materials such as fused quartz and coated with a film. The two sides of the lens are flat, which are the first optical surface 9-1 and the second optical surface 9-2, respectively. The main laser incident surface is coated with a main laser wavelength λ1 antireflection film, and the opposite surface should meet the conditions of high reflection to the probe laser wavelength λ2 and high transmission to the main laser wavelength λ1. The second optical surface 9-2 of the optical flat 9 is the reference surface, and the surface shape of the first optical surface 9-1 and the second optical surface 9-2 requires PV less than λ / 4 and RMS less than λ / 20, where λ is 632.8 nm. The first optical surface 9-1 of the optical flat 9 is coated with a high-transmission film for wavelength λ1, and the second optical surface 9-2 of the optical flat 9 is coated with a film layer with high transmission for wavelength λ1 and high reflection for wavelength λ2.

[0029] The probe laser 4 can be a commercial single-mode fiber laser, and the central wavelength λ2 is separated from the main laser wavelength λ1 by more than 50 nm to meet the use requirements of the fiber wavelength division multiplexer 7, and the output power meets the detection requirements of the second photodetector 11.

[0030] The fiber beamsplitter 5 can be a commercial 1×N polarization maintaining fiber beamsplitter 5, and the input fiber model of the fiber beamsplitter 5 matches the output fiber model of the probe laser 4. The fiber beamsplitter 5 can equally divide the output laser power into N paths, which is the same as the number of beams in the main laser array.

[0031] The (6+1) x 1 fiber combiner 6 in the above embodiment can adopt 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 center signal fiber, and are fused together with the double-clad output fiber after fusion tapering, and the signal fiber signal needs to be matched with the signal of the output fiber of the fiber splitter 5.

[0032] The adaptive fiber collimator 8 can adopt a commercial fiber collimator with tilt aberration correction function. The collimator is highly transparent to both the main laser wavelength λ1 and the probe laser wavelength λ2. The pigtail type of the adaptive fiber collimator 8 is the same as that of the output double-clad fiber of the (6+1) x 1 fiber combiner 6. The number of units and the arrangement of the adaptive fiber collimator 8 array are the same as those of the main laser array, and can strictly correspond one by one.

[0033] The fiber wavelength division multiplexer 7 can adopt a commercial fiber wavelength division multiplexer 7, whose input wavelengths are 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. The output fiber type of the fiber wavelength division multiplexer 7 is matched with the pump arm fiber type of the (6+1) x 1 fiber combiner 6.

[0034] The first photodetector 10 can adopt a commercial fiber-coupled photodetector, whose response band covers the main laser wavelength, the detection sensitivity is matched with the output optical power, and the pigtail type is matched with the input fiber type of the fiber wavelength division multiplexer 7. The response bandwidth meets the signal acquisition requirements of the control module 12.

[0035] The second photodetector 11 can adopt a commercial fiber-coupled photodetector, whose response band covers the probe light wavelength, the detection sensitivity is matched with the output optical power, and the pigtail type is matched with the input fiber type of the fiber wavelength division multiplexer 7. The response bandwidth meets the signal acquisition requirements of the control module 12.

[0036] The control module 12 can be developed by using a single-chip microcomputer, FPGA, DSP and other signal processors, and can receive electrical signals from each photodetector and generate corresponding voltage control signals to be 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 adopt an optimization algorithm such as hill climbing method. The electrical signals output by each photodetector are controlled to be preset values, thereby realizing the parallelism of all array beam optical axes.

[0037] Specifically, the system realizes the working process of tilt aberration detection and correction, which includes the following steps: S1, probe light path calibration: 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.

[0038] S2, Main optical path calibration; 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.

[0039] 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 keeping each probe laser 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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