A compact laser beam combining quality detection system and method based on a microlens array

Abstract

The application provides a compact laser beam combination quality detection system and method based on a microlens array, which comprises an optical signal detection part and a signal processing system, the optical signal detection part comprises an optical system and a detector, the optical system divides complete laser beams passing through a beam combination system into multiple micro light waves and then converges the multiple micro light waves, the detector detects the light intensity of each micro light wave and records the focus point position, and the signal processing part judges the laser beam combination quality according to the light intensity and the focus point position information obtained by the detector. The compact laser beam combination quality detection system and method based on the microlens array can realize accurate detection of the laser beam combination quality by using only one microlens array and one detector, has a simple structure, a short optical path, and an output signal which does not need complex processing and is convenient to use.

Description

Technical Field

[0001] This invention relates to the field of laser shaping output testing technology, specifically to a compact laser beam combining quality testing system and method based on a microlens array. Background Technology

[0002] Lasers are one of the most significant inventions of the 20th century, with widespread applications in medicine, military, communications, and industry. A single laser emits only a single wavelength, but in some industries, two or more laser beams are needed to irradiate matter to produce complex effects for specific applications. For example, in the most basic field of laser lighting, white light is typically obtained by combining two or more laser beams of different wavelengths. Laser beam combining methods include reflection combining, lens combining, and grating combining. Many laser beam combining devices have been invented, but the combined light from multiple beams often enters the optical fiber directly without specialized optical processing, resulting in inconsistent beam quality.

[0003] The quality of the combined laser beam can be directly judged by human observation, but human observation is too subjective, highly dependent on the observer's state and eyesight, and prolonged staring at a laser can cause significant damage to the eyes. Therefore, camera observation is often used to determine the beam combination quality. Existing laser beam combination quality detection systems have many problems. Some detection systems combine opto-mechanical systems, using mechanical moving parts for detection, which requires high stability; others have complex optical systems, long laser beam paths, require large workspaces, and are costly.

[0004] Therefore, providing a laser beam combining quality detection system with a simple structure that can quickly detect whether the propagation directions of the combined beams are parallel, the lateral offset of the combined beams, and whether the spatial positions of the two beams overlap after combining is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The primary objective of this invention is to provide a compact laser beam combining quality detection system based on a microlens array, addressing the problem that the parallelism and lateral offset of beam combining in existing technologies are difficult to judge intuitively.

[0006] Therefore, the above-mentioned objectives of the present invention are achieved through the following technical solutions:

[0007] A compact laser beam combining quality detection system based on a microlens array, characterized in that:

[0008] The system includes an optical signal detection section and a signal processing system. The optical signal detection section includes an optical system and a detector. The optical system is a microlens array that splits the complete laser beam after passing through the beam combining system into multiple tiny light waves, which are then converged. The detector detects the intensity of each tiny light wave and records the focal point position. The signal processing section, an information processing system, determines the laser beam combining quality based on the intensity and focal point position information obtained by the detector. When detecting the beam combining quality of the laser beam, this detection system includes the following steps:

[0009] S1, the focal point position of the laser from the second laser is obtained through the detector.

[0010] S2, Calculate the average tilt angle of the laser incident from the second laser. in θ i Let represent the angle between the laser beam and the optical axis when the laser passes through the i-th microlens, where h i Let θ represent the vertical distance between the focal point of the i-th microlens and the focal point of the combined beam on the focal plane after passing through the i-th microlens, let θ represent the average angle between the second laser and the optical axis when passing through the 1-N microlenses, let f represent the focal length of the microlens, let i represent the microlens number, and let N represent the total number of microlenses in the microlens array, where 1≤i≤N.

[0011] S3, turn off the second laser, turn on the first laser, and repeat steps S1 and S2 to obtain the average tilt angle θ′ of the laser incident from the first laser.

[0012] S4, calculate the relative tilt angle θ″ between the combined beams after passing through the beam combiner, θ″=|θ-θ′|θ;

[0013] S5, turn on the second laser, repeat step S1, the detector is located at the focal plane to collect the position information of the center point of the light spot x. i1 Simultaneously collect light intensity information p i1 The amplitude of the output signal waveform is used as the coordinate system, with position information as the x-axis and light intensity information as the y-axis. N (x, y) values ​​are plotted on the coordinate system. i1 p i1 ) points, fit these points with a curve, and then record the x-coordinate x1 of the highest point of the curve, which is the point of maximum light intensity;

[0014] S6, turn off the second laser, turn on the first laser, repeat step S5, and obtain the x-coordinate x2 of the highest point of the second curve;

[0015] S7, calculate the lateral offset x of the two laser beams after passing through the beam combiner, x = |x1 - x2|cosθ.

[0016] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0017] As a preferred embodiment of the present invention: step S1 includes turning off the first laser, turning on the second laser, the laser beam being split into many tiny light waves by the microlens array after passing through the beam combiner and converging at the focal plane of the microlens array, the CCD detector being located at the focal plane to collect the focal point position information, and simultaneously recording the focal point position information, and calculating the distance between the two points, that is, the vertical distance h between the focal point of the i-th microlens and the focal point of the combined light beam on the focal plane after passing through the i-th microlens. i .

[0018] As a preferred technical solution of the present invention: in step S7, the lateral offset x of the two laser beams after passing through the beam combining device is calculated.

[0019] When two laser beams are combined by a beam combiner and the beams are incident parallel to the optical axis, x = |x1 - x2|.

[0020] When two laser beams pass through a beam combiner and are incident at an angle relative to the optical axis, x = |x1 - x2|cosθ, where θ is the average angle of incidence of the second laser beam. The value of x is used to determine whether the two beams overlap after passing through the beam combiner. The closer the value of x is to zero, the higher the degree of overlap between the two laser beams.

[0021] As a preferred technical solution of the present invention: In step S4, if the beams are relatively tilted, i.e. θ″≠0, the lasers need to be adjusted to make them parallel to each other before proceeding to step S5.

[0022] As a preferred technical solution of the present invention: the microlens array is a fused silica microlens array with an array size of 10mm×10mm×1.2mm, a wavelength range of 400-900nm, a focal length of 5.6mm, and a diameter of 146μm for each microlens.

[0023] The second objective of this invention is to provide a compact laser beam combining quality detection method based on a microlens array, addressing the problems in the prior art.

[0024] Therefore, the above-mentioned objectives of the present invention are achieved through the following technical solutions:

[0025] A compact laser beam combining quality detection method based on microlens arrays, characterized by the following steps:

[0026] S1. Are the complete laser propagation directions of the beam combining system parallel to each other? The first laser is turned off, the second laser is turned on, and after passing through the beam combiner, the laser beam is split into many tiny light waves by the microlens array and converges at the focal plane of the microlens array. The CCD detector is located at the focal plane to collect the focal point position information and simultaneously record the focal point position information. The distance between these two points is calculated, i.e., the perpendicular distance h between the focal point of the i-th microlens and the focal point of the combined beam on the focal plane after passing through the i-th microlens. i ;

[0027] S2, when h i When the incident light beam is parallel to the optical axis, determine if the incident light beam is parallel to the optical axis; for laser beams incident at an angle, calculate the angle of inclination. Repeatedly calculate N θ i Calculate the average tilt angle of the laser incident from the second laser. in θ i This represents the angle between the laser beam and the optical axis when the laser passes through the i-th microlens. θ The value represents the average angle between the laser beam and the optical axis when the laser passes through the 1st to Nth microlenses, f represents the focal length of the microlens, i represents the microlens number, and N represents the total number of microlenses in the microlens array, where 1≤i≤N;

[0028] S3, turn off the second laser, turn on the first laser, and repeat steps S1 and S2 to obtain the average tilt angle θ′ of the laser incident from the first laser.

[0029] S4. Calculate the relative tilt angle θ″ between the beams combined by the beam combiner. θ″ = |θ - θ′|. The value of θ″ is used to determine the relative tilt of the beams combined by the beam combiner.

[0030] S5, turn off the first laser, turn on the second laser, repeat step S1, and the detector is located at the focal plane to collect the position information of the center point of the light spot x. i1 At the same time, it is also necessary to collect light intensity information p i1 The amplitude of the output signal waveform is used as the coordinate system, with position information as the x-axis and light intensity information as the y-axis. N (x, y) values ​​are plotted on the coordinate system. i1 p i1 ) points, fit these points with a curve, and then record the x-coordinate x1 of the highest point of the curve, which is the point of maximum light intensity;

[0031] S6, turn off the second laser, turn on the first laser, repeat step S5, and obtain the x-coordinate x2 of the highest point of the second curve;

[0032] S7, calculate the lateral offset x of the two laser beams after passing through the beam combiner.

[0033] When two laser beams are combined by a beam combiner and the beams are incident parallel to the optical axis, x = |x1 - x2|.

[0034] When two laser beams are incident at an angle relative to the optical axis after passing through a beam combiner, x = |x1 - x2|cosθ, where θ is the average angle of incidence of the second laser. The value of x is used to determine whether the two beams overlap after passing through the beam combiner; the closer the value of x is to zero, the higher the degree of overlap between the two lasers.

[0035] In step S4, if the combined beams are relatively tilted, i.e., θ″≠0, the lasers need to be adjusted to make them parallel to each other before proceeding to step S5.

[0036] Compared with existing technologies, the compact laser beam combining quality detection system and method based on a microlens array of the present invention has the following advantages: The present invention uses only a microlens array and a detector to detect the tilt angle and lateral offset of the combined laser beam. The short optical path and low laser loss result in high accuracy. The present invention has a simple structure and small footprint. By utilizing different selections of the microlens array, the present invention can be applied to the ultraviolet, visible, and infrared bands, expanding the wavelength range of laser beam combining quality detection to the ultraviolet and infrared bands, thus covering a wide range of wavelengths. The output signal of the compact laser beam combining quality detection system based on a microlens array of the present invention does not require complex processing and is easy to use. The two output parameters, angle and offset, clearly characterize whether the combined beams are parallel to each other and whether they are completely combined after passing through the beam combining system. The compact laser beam combining quality detection system and method based on a microlens array of the present invention detects the quality of the combined laser beam, solving the problem that the parallelism and lateral offset of the combined beams are difficult to judge intuitively. It has good application prospects in laser beam combining to fuse different wavelength information and improve laser power in fields such as medicine, military, communications, and industry. Attached Figure Description

[0037] Figure 1 This is an overall structural diagram of a compact laser beam combining quality detection system based on a microlens array according to the present invention;

[0038] Figure 2 This is a signal processing flowchart of a compact laser beam combining quality detection system based on a microlens array according to the present invention.

[0039] Figure 3 This is a schematic flowchart of a compact laser beam combining quality detection method based on a microlens array according to the present invention.

[0040] Figure 4 This is a schematic diagram illustrating the principle of beam combining laser angle detection according to the present invention;

[0041] Figure 5 This is a schematic diagram illustrating the principle of beam combining laser lateral offset detection according to the present invention;

[0042] In the attached diagram, 1 is a wavelength beam combiner; 2 is a microlens array; 3 is a CCD detector; and 4 is an information processing system. Detailed Implementation

[0043] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0044] Example 1

[0045] This invention discloses a compact laser beam combining quality detection system based on a microlens array, comprising an optical signal detection section and a signal processing section. The optical signal detection section includes an optical system and a detector. The optical system splits a complete laser beam into many tiny light waves and then converges them. The detector detects the intensity of these tiny light waves and records the focal point position. This detection system is used to detect the beam combining quality of multiple laser beams and is applicable to laser beam combining of any wavelength and any number, as well as beam combining systems based on different beam combining principles.

[0046] This invention is based on Figure 1 Taking a laser and beam combining system as an example, this laser beam combining quality detection system is described: The first and second lasers are two semiconductor lasers, with the second laser emitting blue light at a wavelength of 450nm and the first laser emitting red light at a wavelength of 685nm. The beam combining system consists of a wavelength beam combiner 1 with the light emitted by the two semiconductor lasers at an angle of 45°, resulting in the two beams merging after passing through the beam combiner. The microlens array 2 is a fused silica microlens array with an array size of 10mm × 10mm × 1.2mm, a wavelength range of 400-900nm, and a focal length of 5.6mm. The diameter of each microlens is 146μm. After passing through the microlens array, the combined light is split into many small light waves, each of which is focused onto the focal plane by a corresponding microlens. The detector is a CCD detector 3, with a sufficiently large maximum signal charge Q in the CCD unit potential well to ensure sufficient response signal from the CCD under high-power laser irradiation. When visible light shines on a CCD, the position of the photosensitive pixels within the entire CCD pixel array is easily determined (the center point of the photosensitive area is recorded when recording position information). Furthermore, the free electrons generated by each pixel unit are collected by the CCD and converted into a voltage signal output. The amplitude of the output signal waveform reflects the amount of light converted into charge by each pixel unit, i.e., light intensity information. Therefore, a CCD detector has the ability to record the focal point position and intensity of each tiny light wave on the focal plane.

[0047] In the signal processing section, the information processing system 4 determines the laser beam combining quality based on the light intensity and focal point position information acquired by the CCD detector. The signal processing flowchart is as follows: Figure 2As shown, firstly, it is detected whether the propagation directions of the combined beams are parallel to each other. With the first laser on and the second laser off, for a certain microlens, the CCD detector measures the distance h between the focal point and the focal point on the focal plane. i Ideally, when the laser is incident parallel to the optical axis, h i =0. For a laser beam incident at an angle, its incident angle is... Where f represents the focal length of the microlens. The focal length θ of all microlenses is measured. i It can calculate the average tilt angle of laser incident. Similarly, with the second laser on and the first laser off, the average tilt angle θ′ of the laser incident beam is calculated, and θ and θ′ are compared to determine the relative tilt between the combined beams after passing through the beam combiner. Then, the lateral offset of the combined beam is detected. With the first laser on and the second laser off, the laser emitted by the first laser, after passing through the microlens array, can be observed at N focal points on the CCD. The optical signal detection section acquires the position information x of the N focal points. i1 Light intensity information p i1 Fit these position and light intensity information into a coordinate system, i.e., (x... i1 p i1 As a point in the coordinate system, there are N such points. Using curve fitting, the coordinates x1 of the highest point on the curve, i.e., the point of maximum light intensity, are recorded. Similarly, with red light on and blue light off, the position information x of the N focal points can be obtained. i2 Light intensity information p i2 A curve is fitted, and the coordinates x2 of the highest point of the curve, i.e., the point of maximum light intensity, are recorded. Then, when the two laser beams are incident parallel to the optical axis of the microlens array after passing through the beam combining system, the lateral offset x = |x1-x2|. When incident at an angle, the lateral offset x = |x1-x2|cosθ (the beam is incident at an angle relative to the optical axis, where θ is the average angle of incidence mentioned above, and it is assumed that θ = θ′ has been adjusted at this time). The value of x is used to determine whether the two beams overlap after passing through the beam combining device. The closer the value of x is to zero, the higher the degree of laser overlap.

[0048] like Figure 3 As shown, the present invention provides a compact laser beam combining quality detection method based on a microlens array, which includes the following steps during detection:

[0049] S1, turn off the second laser and turn on the first laser. After passing through the beam combiner, the laser beam is split into many tiny light waves by the microlens array and converges at the focal plane of the microlens array. The CCD detector is located at the focal plane to collect the focal point position information. At the same time, it also needs to record the focal point position information (located on the optical axis of each microlens). Calculate the distance between the two points, that is, the perpendicular distance h between the focal point of the i-th microlens and the focal point of the combined beam on the focal plane after passing through the i-th microlens. i .

[0050] S2, calculate the tilt angle of the light ray. Repeatedly calculate N θ i Calculate the average tilt angle of blue light incident.

[0051] S3, turn off the first laser, turn on the second laser, repeat steps S1 and S2 to obtain the average tilt angle θ′ of the red light incident;

[0052] S4. Compare θ and θ′ to determine the relative tilt of the combined beam after passing through the beam combiner.

[0053] S5, turn off the second laser, turn on the first laser, same as step S1, the CCD detector is located at the focal plane to collect the position information of the center point of the light spot x. i1 At the same time, it is also necessary to collect light intensity information p i1 (Represented by the amplitude of the output signal waveform), with position information as the x-axis and light intensity information as the y-axis, mark N (x, y) values ​​in the coordinate system. i1 p i1 ) points, fit these points with a curve, and then record the coordinates x1 of the highest point of the curve, which is the point of maximum light intensity;

[0054] S6, turn off the first laser, turn on the second laser, repeat step S5, and obtain the coordinates x2 of the highest point of the second curve;

[0055] S7. Calculate the lateral offset x = |x1-x2| or x = |x1-x2|cosθ after the two laser beams pass through the beam combiner to determine whether the two beams are completely overlapped or there is still a lateral offset, indicating that they are not completely combined.

[0056] In this invention, the problem of relative tilt between the laser beams needs to be addressed after step S4; otherwise, steps S5-S7 are meaningless. Two laser beams that are tilted to each other will not overlap after passing through the optical system, and there will definitely be a lateral offset. Therefore, it is necessary to adjust the laser beams to be parallel before proceeding with steps S5-S7. In step S7, when the laser beams are not incident parallel to the optical axis, the formula x = |x1 - x2|cosθ is required, where θ is the average tilt angle of incidence θ (θ = θ′). The reason is that when the two laser beams are incident at an angle, the distance between the coordinates of the two points of maximum light intensity on the focal plane is not equal to the lateral offset, and it needs to be multiplied by the cosine value of the average tilt angle of incidence.

[0057] The detection principle in this invention can be used Figure 4 , 5 Detailed explanation. Figure 4This is a schematic diagram illustrating the principle of beam combining laser angle detection according to the present invention. The diagram shows the optical path of the laser after passing through a microlens. F, F′, and G represent the object-side focal point, image-side focal point, and focal point (the intersection point of all light rays passing through this microlens on its focal plane), respectively. θ i h i The meaning is the same as before. In an ideal optical system, parallel incident light must intersect at a point on the image-side focal plane. Drawing an auxiliary ray passing through the object-side focal point, which exits parallel after passing through a microlens, we can obtain the diagram showing all rays intersecting at a point G. This is easily seen in the diagram. but The figure only shows the light rays passing through one microlens. The average tilt angle of the laser incident light can be obtained by averaging the light rays through N microlenses. It is worth noting that the above discussion is based on the premise of an ideal optical system. In actual optical systems, there are various errors, such as deviations in the position of the focal plane, which prevent all light rays from converging well at a single point. However, the intersection of these rays with the focal plane must still be located near that point. Therefore, it is sufficient to obtain the center position of the brightest photosensitive area.

[0058] Figure 5 This is a schematic diagram illustrating the principle of a combined laser lateral offset detection method according to the present invention. The solid and dashed lines represent the lasers emitted by the first and second lasers, respectively. Typically, the laser beam is a Gaussian beam, therefore... Figure 5 The solid and dashed lines below represent the incident Gaussian beams. The expression for a Gaussian beam is: Where E and E0 represent the current and maximum amplitudes, ω0 is the beam waist radius, ω(z) is the fundamental mode spot radius, and r is the spot radius at that location. This invention does not focus on the parameters of the Gaussian beam, but only on the center point of the Gaussian beam. As mentioned earlier, the two laser beams are allowed to enter the microlens array sequentially, meaning that only one beam is in the optical system at any given time. The object-side and image-side focal points of each microlens are marked in the figure (there are N microlenses in total, and 4 microlenses are shown in the figure to represent the entire microlens array). Even though the lasers shown by the solid line and the lasers shown by the dashed line converge at the same focal point, the light intensities of these two beams illuminating a single microlens differ. Different light intensities can be obtained at the same focal point, thus yielding N (x) i1 p i1 ) points and N (x) i2 p i2 The system identifies points and then fits two curves based on these points, as shown in the upper part of the figure. The fitted curves theoretically conform to a Gaussian function. This invention obtains the signal output waveform from the CCD, therefore the amplitude of the waveform directly represents the light intensity information. After curve fitting, the highest point of the obtained curve is the center of the Gaussian beam. Calculating the distance between the coordinates of the highest points of the two curves yields the lateral offset x = |x1 - x2| of the two laser beams after passing through the beam combiner. Figure 5In this case, the light rays after passing through the beam combiner are not necessarily parallel to the optical axis, so the light rays after passing through the microlens may not converge at the focal point of the microlens, but the light rays will definitely converge at a focal point on the focal plane, such as... Figure 4 As shown in the figure, the lateral offset x = |x1-x2|cosθ.

[0059] In this invention Figure 4 Figure 5 Drawing only one or a few microlenses in a microlens array does not represent the actual number of microlenses in the array.

[0060] This invention discloses a compact laser beam combining quality detection system and method based on a microlens array. The core of this system lies in the microlens array. To improve detection capabilities, one can modify the microlens array's material, size, transmission band, and focal length. The laser and laser beam combining device are not the primary focus of this invention and can be arbitrarily replaced. CCD detection technology is used to detect light intensity; it is a mature technology capable of achieving rapid response. The output signal requires no complex processing and is easy to use.

[0061] This invention discloses a compact laser beam combining quality detection system and method based on a microlens array. Compared with existing technologies, it uses only one optical element (microlens array) and one detection element (CCD) to achieve accurate detection of laser beam combining quality. The structure is simple, the overall optical path is short, and the required equipment footprint is significantly reduced. It covers a wide wavelength range, enabling ultraviolet and infrared beam combining quality detection, and has broad application prospects. Medical, military, communication, and industrial fields all require laser beam combining to fuse different wavelength information and improve laser power, and the quality detection of laser beam combining is an indispensable step.

[0062] The above specific embodiments are used to explain and illustrate the present invention, and are only preferred embodiments of the present invention, not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A compact laser beam combining quality detection system based on a microlens array, characterized in that: The system includes an optical signal detection section and a signal processing system. The optical signal detection section includes an optical system and a detector. The optical system is a microlens array that splits the complete laser beam after passing through the beam combining system into multiple tiny light waves, which are then converged. The detector detects the light intensity of each tiny light wave and records the focal point position. The signal processing system determines the laser beam combining quality based on the light intensity and focal point position information obtained by the detector. When detecting the beam combining quality of the laser beam, this detection system includes the following steps: S1, turn off the first laser, turn on the second laser, and obtain the focal point position of the second laser using a detector; S2, Calculate the average tilt angle of the laser incident from the second laser. ,in θ Indicates the laser passes through the first The angle between each microlens and the optical axis, where, , Indicates the first The focal point of the microlens and the combined beam of light pass through the first... The perpendicular distance between the focal points of the microlenses on the focal plane, θ represents the average angle between the second laser and the optical axis when the second laser passes through the 1st to Nth microlenses. Indicates the focal length of the microlens. This indicates the microlens number, and N represents the total number of microlenses in the microlens array. ; S3, turn off the second laser, turn on the first laser, and execute the steps of S1 (obtaining the focal point position of the first laser through the detector) and S2 (calculating the average tilt angle of the first laser incident laser) to obtain the average tilt angle of the first laser incident laser. ; S4, Calculate the relative tilt angle between the combined beams after passing through the beam combiner. ”, "=| - |; S5, turn off the first laser, turn on the second laser, repeat step S1, and the detector is located at the focal plane to collect the position information of the center point of the light spot. Simultaneously collect light intensity information The amplitude of the output signal waveform is used as the indicator, with position information as the x-axis and light intensity information as the y-axis, and the values ​​are plotted on a coordinate system. indivual Points are fitted with a curve, and the x-coordinate of the highest point of the curve, i.e., the point of maximum light intensity, is recorded. ; S6, turn off the second laser, turn on the first laser, switch to the first laser, and perform the same measurement and fitting steps as in step S5 to obtain the x-coordinate of the highest point of the second curve. ; S7, calculate the lateral offset x of the two laser beams after passing through the beam combiner. .

2. The compact laser beam combining quality detection system based on microlens array as described in claim 1, characterized in that: Step S1 includes turning off the first laser, turning on the second laser, and after the laser beam passes through a beam combiner, it is split into many tiny light waves by a microlens array and converges at the focal plane of the microlens array. A CCD detector is located at the focal plane to collect the focal point position information and simultaneously record the focal point position information, calculating the first... The focal point of the microlens and the combined beam of light pass through the first... The vertical distance between the focal points of the microlenses on the focal plane .

3. The compact laser beam combining quality detection system based on microlens array as described in claim 1, characterized in that: In step S7, the lateral offset x of the two laser beams after passing through the beam combiner is calculated. When two laser beams pass through a beam combiner, and the beams are incident parallel to the optical axis... ; When two laser beams are combined and incident at an angle relative to the optical axis, ,in, The value is used to determine whether the two beams overlap after passing through the beam combiner. The closer the value is to zero, the higher the degree of overlap between the two lasers.

4. The compact laser beam combining quality detection system based on microlens array as described in claim 1, characterized in that: In step S4, if the combined beams are tilted relative to each other, that is... When '≠0', the lasers need to be adjusted to make them parallel to each other before proceeding to step S5.

5. The compact laser beam combining quality detection system based on a microlens array as described in claim 1, characterized in that: The microlens array is a fused silica microlens array with an array size of 10mm×10mm×1.2mm, a wavelength range of 400-900nm, a focal length of 5.6mm, and a diameter of 146μm for each individual microlens.

6. The compact laser beam combining quality detection system based on a microlens array as described in claim 1, characterized in that: The detector is an array of photosensitive elements, and each photosensitive element includes, but is not limited to, CCD and CMOS, and the photosensitive material includes, but is not limited to, silicon and germanium semiconductor materials.

7. A compact laser beam combining quality detection method based on a microlens array, characterized in that: Includes the following steps: S1, Are the complete laser propagation directions of the beam combining system parallel to each other? The first laser is turned off, the second laser is turned on, and after passing through the beam combiner, the laser beam is split into many tiny light waves by the microlens array and converges at the focal plane of the microlens array. The CCD detector is located at the focal plane to collect the focal point position information and simultaneously record the focal point position information. The distance between the two points is calculated, i.e., the first... The focal point of the microlens and the combined beam of light pass through the first... The vertical distance between the focal points of the microlenses on the focal plane ; S2, when When the laser is incident parallel to the optical axis, determine the incident laser beam; for lasers incident at an angle, calculate the angle of inclination. Repeated calculation indivual Calculate the average tilt angle of the laser incident from the second laser. ,in θ Indicates the laser passes through the first The angle between the microlens and the optical axis, θ This represents the average angle between the laser beam and the optical axis as the laser passes through the 1st to Nth microlenses. Indicates the focal length of the microlens. This indicates the microlens number, and N represents the total number of microlenses in the microlens array. ; S3, turn off the second laser, turn on the first laser, and repeat steps S1 and S2 to obtain the average tilt angle of the laser incident from the first laser. ; S4, Calculate the relative tilt angle between the combined beams after passing through the beam combiner. ”, "=| - |, The value of '' is used to determine the relative tilt between the beams of light combined by the beam combiner. S5, turn off the first laser, turn on the second laser, repeat step S1, and the detector is located at the focal plane to collect the position information of the center point of the light spot. At the same time, it is also necessary to collect light intensity information. The amplitude of the output signal waveform is used as the indicator, with position information as the x-axis and light intensity information as the y-axis, and the values ​​are plotted on a coordinate system. indivual Points are fitted with a curve, and the x-coordinate of the highest point of the curve, i.e., the point of maximum light intensity, is recorded. ; S6, turn off the second laser, turn on the first laser, and repeat step S5 to obtain the x-coordinate of the highest point of the second curve. ; S7, calculate the lateral offset x of the two laser beams after passing through the beam combiner. When two laser beams pass through a beam combiner, and the beams are incident parallel to the optical axis... ; When two laser beams are combined and incident at an angle relative to the optical axis, ,in Let be the average tilt angle of the laser incident from the second laser, where The value is used to determine whether the two beams overlap after passing through the beam combiner. The closer the value is to zero, the higher the degree of overlap between the two lasers. In step S4, if the combined beams are tilted relative to each other, that is... When '≠0', the lasers need to be adjusted to make them parallel to each other before proceeding to step S5.

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