A laser auxiliary detection device and a laser detection method

Abstract

This invention belongs to the field of optical equipment testing technology, and discloses a laser-assisted testing device and laser testing method, including a mounting platform, a mounting frame, a laser fixing and supporting mechanism, a single-module photoelectric detection component, and a main control processing unit. The laser fixing and supporting mechanism uses elastic grippers and limiting blocks to achieve rapid coarse positioning of the laser; the device does not include any precision displacement stage, galvanometer, or mechanical adjustment mechanism. The single-module photoelectric detection component includes an electrically adjustable neutral density filter and a CMOS image sensor. During testing, the main control processing unit performs virtual alignment correction, correcting the off-center spot to a virtual central spot image through centroid calculation, image translation, vignetting correction, and distortion correction, while simultaneously calculating multiple sets of parameters. This invention replaces mechanical alignment with an algorithm, achieving the equivalent testing accuracy of precision mechanical alignment under coarse positioning conditions, significantly simplifying the structure, reducing costs, and improving testing efficiency, making it suitable for batch online testing of lasers.

Description

Technical Field

[0001] This invention relates to the field of optical equipment testing technology, and in particular to a laser-assisted testing device and a laser testing method. Background Technology

[0002] As a core component in the optoelectronic field, lasers are widely used in communications, medical applications, industrial processing, scientific research, and many other fields. Their beam parameters, such as optical power, spot diameter, divergence angle, ellipticity, and spot uniformity, directly determine the reliability and performance of their applications. Therefore, accurate detection of these parameters is essential during laser production, debugging, and factory testing. Consequently, laser auxiliary testing devices and methods have become key technologies for ensuring laser product quality. Currently, various laser testing devices and methods have emerged in the industry, all revolving around the acquisition and analysis of laser beam parameters, aiming to achieve rapid evaluation of laser performance and meet the basic needs of industrial-scale batch testing.

[0003] To achieve precise alignment between the laser spot and the detection component, existing detection devices generally employ mechanical alignment schemes using precision displacement stages, galvanometers, or additional position adjustment mechanisms. This not only leads to complex device structures and high manufacturing and maintenance costs, but also necessitates recalibrating the mechanical alignment every time the laser under test is replaced during batch testing, resulting in low detection efficiency. Furthermore, even if preliminary positioning is achieved through mechanical alignment, it is still difficult to completely avoid systematic errors such as vignetting and distortion caused by laser spot deflection, which affect detection accuracy and fail to meet the dual requirements of detection accuracy and efficiency. Summary of the Invention

[0004] The present invention aims to provide a laser-assisted detection device and a laser detection method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A laser-assisted detection device includes: a mounting platform, a mounting frame, a laser fixing and supporting mechanism, a single-module photoelectric detection component, and a main control processing unit; The mounting bracket is connected to the mounting platform; The laser fixing and bearing mechanism includes a positioning cylinder, which is connected to a bracket. The bracket is connected to a mounting frame. Three or more sets of grippers are evenly distributed along the circumference of the inner wall of the positioning cylinder. The grippers are connected to a telescopic rod, which is connected to the inner wall of the positioning cylinder. A spring is sleeved on the outside of the telescopic rod. The two ends of the spring are respectively connected to the grippers and the inner wall of the positioning cylinder. The grippers are connected to a limit block, which is used to abut against the light-emitting end face of the laser under test. The single-module photoelectric detection component includes an electrically adjustable neutral density filter and a CMOS image sensor. The electrically adjustable neutral density filter has multiple switchable levels with different attenuation ratios, and the CMOS image sensor is used to acquire light spot images and output grayscale data. The central axis of the positioning cylinder, the central axis of the filter in the working position of the electrically adjustable neutral density filter, and the central axis of the photosensitive surface of the CMOS image sensor coincide. The main control processing unit is electrically connected to both the electrically adjustable neutral density filter and the CMOS image sensor. The main control processing unit is configured to: determine whether the image is overexposed based on the grayscale values ​​acquired by the CMOS image sensor, and control the electrically adjustable neutral density filter to switch settings; perform virtual alignment correction on the acquired spot image, including calculating the spot centroid coordinates, virtually translating the image to move the centroid to the image center, and applying pre-calibrated vignetting correction coefficients and distortion correction models; calculate the optical power based on the grayscale integral of the virtually corrected image, and simultaneously calculate the spot diameter, divergence angle, ellipticity, and spot uniformity parameters on the virtually corrected image; and output the detection results. The device does not contain any precision displacement stage, galvanometer, or mechanical adjustment mechanism for spot alignment.

[0006] Preferably, each of the springs has the same stiffness, and the springs, in their natural state, cause the inner diameter of the gripper to be smaller than the minimum expected diameter of the laser under test.

[0007] Preferably, the end of the gripper away from the limiting block opens outward in a flared shape to guide lasers of different diameters to be inserted smoothly.

[0008] Preferably, the CMOS image sensor is a global shutter type area array sensor with a rectangular photosensitive area, a long side dimension of not less than 12mm, a short side dimension of not less than 9mm, and a dynamic range of ≥70dB.

[0009] Preferably, it also includes a light shield, which is a cylindrical structure with openings at the top and bottom. The light shield is fitted onto the outside of the mounting frame, the laser fixing and bearing mechanism, the single-module photoelectric detection component and the main control processing unit in cooperation with the mounting platform. The light shield is provided with a cable outlet.

[0010] A laser detection method, based on the above-mentioned apparatus, includes the following steps: S1. Insert the laser to be tested into the positioning cylinder, so that the gripper holds the laser housing under the action of the spring until the laser output end face contacts the limiting block. S2. The main control processing unit automatically controls the switching of the electrically adjustable neutral density filter based on the grayscale value of the image acquired by the CMOS image sensor, so that the image grayscale is within a suitable range. S3. The main control processing unit performs virtual alignment correction on the acquired spot image to correct the off-center spot into a virtual center spot image. S4. The main control processing unit calculates the optical power based on the grayscale integral of the virtual center spot image, and simultaneously calculates the spot diameter, divergence angle, ellipticity and spot uniformity parameters on the virtual center spot image. S5. Output the detection results.

[0011] Preferably, the virtual alignment correction in step S3 includes: calculating the centroid position of the spot based on the grayscale distribution of the original spot image; virtually translating the original image so that the centroid of the spot moves to the center of the image; applying a pre-calibrated vignetting correction coefficient to perform pixel-by-pixel gain compensation on the translated image; and applying a pre-calibrated distortion correction mapping function to perform geometric correction on the image to obtain a virtual center spot image.

[0012] Preferably, it further includes a pre-calibration step S0, which is performed before S1: S0. Perform vignetting calibration on the CMOS image sensor using a uniform surface light source to generate vignetting correction coefficients; perform distortion calibration using a checkerboard calibration board and solve for the distortion correction mapping function; perform power calibration using a standard optical power meter to establish the mapping relationship between the grayscale integral value and the actual power, and obtain the power conversion coefficients. The eccentricity correction coefficient was calibrated using a standard laser and a precision displacement stage, and the correction relationship between the eccentricity distance of the spot centroid and the power measurement error and diameter measurement error was established.

[0013] Preferably, in step S4: optical power according to Calculation, where The power conversion factor, The grayscale integral value of the virtual center spot image. The transmittance of an electrically adjustable neutral density filter. The distance from the centroid of the light spot to the center of the image. For about The monotonically increasing function is determined by calibration in step S0. divergence angle Calculation, where , The diameter of the light spot measured on the virtual center light spot image. For about The monotonically decreasing function is determined through the calibration in step S0. This is the fixed distance from the positioning surface of the limit block to the photosensitive surface of the CMOS image sensor.

[0014] Preferably, the step of bringing the image grayscale to a suitable range in step S2 includes: the main control processing unit preferentially controlling the switching position of the electrically adjustable neutral density filter; if the image is still overexposed after switching to the maximum attenuation position, the exposure time of the CMOS image sensor is further reduced; if the image is still too weak after switching to the minimum attenuation position, the exposure time and gain of the CMOS image sensor are further increased.

[0015] The beneficial effects of this technical solution compared to existing technologies are as follows: (1) This technical solution eliminates the need for a precise mechanical alignment mechanism, achieving rapid coarse positioning of the laser solely through the cooperation of springs, grippers, and limiting blocks. This significantly simplifies the structure, reduces manufacturing costs, and eliminates the need for recalibration during batch testing, thus improving testing efficiency. Furthermore, it proposes a virtual alignment correction and eccentricity correction mechanism. By calculating the centroid of the spot, virtually shifting the image, performing vignetting correction, and correcting distortion, the eccentric spot is corrected into a virtual central spot image. A correction function based on the eccentricity distance is introduced into the calculation of optical power and divergence angle, and a correction relationship between the eccentricity distance and measurement error is established through pre-calibration. Under coarse positioning conditions, it achieves testing accuracy equivalent to that of precision mechanical alignment, overcoming the technical prejudice in this field that "alignment accuracy must depend on mechanical accuracy."

[0016] (2) An adaptive exposure control strategy is adopted, which links filter level switching, exposure time, and gain in three stages: the electrically adjustable neutral density filter is switched first; if the image is still overexposed after switching to the maximum attenuation level, the CMOS exposure time is further reduced; if the image is still too weak after switching to the minimum attenuation level, the CMOS exposure time and gain are further increased. This allows the device to automatically adapt to lasers of different power levels from milliwatts to 10 watts without manual intervention, and it has strong compatibility, solving the problem of poor adaptability of traditional detection devices to lasers with a wide power range.

[0017] (3) The light spot image is acquired by a single CMOS image sensor. The main control processing unit synchronously calculates five parameters on the same frame of virtual center light spot image: light power, light spot diameter, divergence angle, ellipticity and light spot uniformity. All parameters come from the same frame of image at the same time and under the same light spot state. The parameters have natural physical consistency, avoiding the data mismatch problem caused by time-division and device-division measurement, and the detection results are more reliable. Attached Figure Description

[0018] Figure 1 Provided for the present invention; Figure 2 Provided for the present invention; Figure 3 Provided for the present invention; Figure 4 Provided for the present invention; Figure 5 Provided for the present invention; Reference numerals in the attached drawings: 1. Mounting platform; 2. Light shield; 3. Gripper; 4. Mounting bracket; 5. Positioning cylinder; 6. Cable outlet; 7. Motorally adjustable neutral density filter; 8. CMOS image sensor; 9. Main control processing unit; 10. Telescopic rod; 11. Limiting block; 12. Spring; 13. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: like Figure 1-4 The laser-assisted detection device shown includes a mounting platform 1, a mounting frame 4, a laser fixing and bearing mechanism, a single-module photoelectric detection component, and a main control processing unit 10.

[0020] The mounting bracket 4 is fixedly connected to the mounting platform 1. The laser fixing and bearing mechanism includes a positioning cylinder 6, which is fixedly connected to the mounting bracket 4 via a bracket 5. Three sets of grippers 3 are evenly distributed along the circumference of the inner wall of the positioning cylinder 6 at 120 degrees. Each set of grippers 3 is connected to a telescopic rod 11, which is connected to the inner wall of the positioning cylinder 6. A spring 13 is sleeved on the outer side of the telescopic rod 11, and both ends of the spring 13 are connected to the grippers 3 and the inner wall of the positioning cylinder 6, respectively. A limiting block 12 is connected to the bottom end of the grippers 3, and the limiting block 12 is used to abut against the light-emitting end face of the laser under test.

[0021] The top of the gripper 3, away from the limiting block 12, opens outward in a flared shape. This flared structure acts as a guide when the laser is inserted, ensuring that even if the laser diameter has a certain tolerance or the insertion angle is slightly off, it can be smoothly guided into the positioning cylinder 6. Each spring 13 has the same stiffness, and in its natural state, the springs 13 cause the inner diameter formed by the gripper 3 to be smaller than the minimum expected diameter of the laser under test. When lasers of different diameters are inserted, the three sets of grippers 3 produce the same elastic deformation under the action of the springs 13. Because the springs 13 have consistent stiffness and are symmetrically arranged along the circumference, the laser housing is automatically pushed towards the central axis of the positioning cylinder 6, achieving self-adaptive centering.

[0022] The single-module photoelectric detection assembly includes an electrically adjustable neutral density filter 8 and a CMOS image sensor 9, arranged sequentially along the optical axis. The CMOS image sensor 9 is connected to the mounting platform 1. Along the laser beam propagation direction, the electrically adjustable neutral density filter 8 is located between the laser fixing support mechanism and the CMOS image sensor 9; that is, the laser beam is first attenuated by the electrically adjustable neutral density filter 8 before being incident on the photosensitive surface of the CMOS image sensor 9. The electrically adjustable neutral density filter 8 has a rotary structure, with multiple filters of different attenuation ratios evenly distributed along its circumference. The filter settings are switched by rotating the rotary wheel driven by a motor. The CMOS image sensor 9 is used to acquire light spot images and output grayscale data.

[0023] During assembly, the central axis of the positioning cylinder 6, the central axis of the electrically adjustable neutral density filter 8 in its working position, and the central axis of the photosensitive surface of the CMOS image sensor 9 are aligned. This coaxial assembly is ensured by precision machining and positioning pins, achieving a coaxiality better than 0.1 mm.

[0024] The main control processing unit 10 is electrically connected to the electrically adjustable neutral density filter 8 and the CMOS image sensor 9. The main control processing unit 10 is configured to: determine whether overexposure is present based on the grayscale values ​​of the image acquired by the CMOS image sensor 9, and control the electrically adjustable neutral density filter 8 to switch between different settings; perform virtual alignment correction on the acquired spot image; calculate the optical power based on the grayscale integral of the virtually corrected image, and simultaneously calculate the spot diameter, divergence angle, ellipticity, and spot uniformity parameters on the virtually corrected image; and output the detection results. This device does not contain any precision displacement stage, galvanometer, or mechanical adjustment mechanism for spot alignment; all alignment functions are completed by the main control processing unit 10 through algorithms.

[0025] The device also includes a light shield 2, which is a cylindrical structure with openings at the top and bottom, fitted around the mounting frame 4, the laser fixing support mechanism, the single-module photoelectric detection component, and the main control processing unit 10. A cable outlet 7 is located at the bottom of the light shield 2 for leading out cables from the electrically adjustable neutral density filter 8, the CMOS image sensor 9, and the main control processing unit 10. The inner wall of the light shield 2 has matting threads and is coated with a black light-absorbing coating to reduce interference from internal reflected light on the detection.

[0026] like Figure 5 The laser detection method shown is based on the above-described apparatus and includes the following steps: S0, Factory pre-calibration: Before using this device, the following calibration steps must be completed. After calibration, it can be used for a long time without repeated calibration. All calibration parameters are stored in the memory of the main control processing unit.

[0027] 1. Vignette calibration The device is placed in a darkroom environment, and a uniform surface light source (such as an integrating sphere) is placed close to the photosensitive surface of the CMOS image sensor to ensure uniform illumination across the entire image frame. The main control processing unit controls the CMOS image sensor to continuously acquire multiple frames of images and average them to obtain a uniformly illuminated image. The average grayscale value of the central region of the image (e.g., 100 x 100 pixels) is calculated. The vignetting correction coefficient is then calculated using the following formula: in The average gray value of the central region of the image. To uniformly illuminate the image at pixel locations The grayscale value at that location. For each pixel position in the image, this coefficient reflects the degree of response attenuation relative to the central region. The calculated vignetting correction coefficients are stored in the memory of the main control processing unit.

[0028] 2. Distortion calibration A high-precision checkerboard calibration plate (5 mm x 5 mm grid size, with an accuracy better than ±0.01 mm) is placed perpendicular to the optical axis in front of the CMOS image sensor. The main control processing unit controls the CMOS image sensor to acquire images from the calibration plate, and acquires ten to twenty images at different angles and distances.

[0029] The distortion parameters of the lens are determined using Zhang Zhengyou's calibration method. The specific steps are as follows: Collect multiple (e.g., 10-20) images of the chessboard calibration board from different angles and positions; Detect the corner points of the checkerboard pattern in each image and obtain the pixel coordinates of the corner points; Establish the world coordinates of the corner points based on the physical dimensions of the chessboard grid (e.g., grid side length 5mm); By utilizing the correspondence between the pixel coordinates of corner points and world coordinates, the camera's intrinsic and extrinsic parameters can be solved. The distortion model is established as follows: in These are the pixel coordinates in the distorted image. The corrected coordinates, , , , The radial distortion coefficient is... , The tangential distortion coefficient; The least squares optimization algorithm (such as the Levenberg-Marquardt algorithm) is used to simultaneously optimize the intrinsic parameters, extrinsic parameters and distortion coefficients to minimize the sum of squared reprojection errors of all corner points, and finally the distortion coefficients are obtained. The obtained distortion coefficients and camera intrinsic parameters are stored in the memory of the main control processing unit to generate a distortion correction mapping function.

[0030] 3. Power calibration A standard laser was installed in the device using a metrologically calibrated standard optical power meter (traceable to national metrological standards). The grayscale integral values ​​of the laser spot image acquired by the CMOS image sensor and the readings of the standard optical power meter were recorded at multiple different filter settings. For each setting, a linear mapping relationship was established: in The grayscale integral value. The readings are from a standard optical power meter. The power conversion coefficients are solved using least-squares fitting. Transmittance corresponding to different filter settings It is known that the power is measured according to the actual test. calculate.

[0031] 4. Calibration of eccentricity correction coefficient The eccentricity correction coefficient calibration is performed on an independent optical platform, independent of the laser fixing support mechanism of this device. A CMOS image sensor of the same model as this device and a standard laser are fixed on the optical adjustment frame, with their optical axes aligned. A precision displacement stage (this displacement stage is only used for calibration and is not part of this device) is set between the standard laser and the CMOS image sensor to manually change the radial position of the laser beam relative to the CMOS photosensitive surface.

[0032] Record the laser beam at the center position (eccentricity distance) The grayscale integral value output by the CMOS image sensor at that time. Simultaneously record the readings of the standard optical power meter. The eccentricity is gradually increased by using a precision displacement stage. Record different Gray integral value under value and standard optical power meter readings .

[0033] Calculate the power correction factor This coefficient reflects the influence of eccentricity distance on the conversion relationship between grayscale integral value and actual power. It is stored in the main control processing unit's memory in the form of a lookup table or a fitting function. During fitting, Using about the eccentricity distance It is a monotonically increasing function.

[0034] Similarly, record the measured values ​​of the light spot diameter under different eccentric distances. (Readings obtained directly from the image) and from a standard beam quality analyzer. Calculate the diameter correction factor ,Will Stored in the form of a lookup table or a fitted function. During fitting, Using about the eccentricity distance It is a monotonically decreasing function.

[0035] After calibration, the obtained correction coefficients are written into the main control processing unit of this device. During actual testing, the optical power is adjusted according to... Calculation, where The grayscale integral value of the virtual center spot image. The power conversion factor, This represents the transmittance of the filter.

[0036] 5. Distance calibration Fixed distance from the positioning surface of the limiting block to the photosensitive surface of the CMOS image sensor The accuracy is guaranteed by mechanical assembly. After the device is assembled, it is measured and confirmed using a laser rangefinder or a standard length block, and the value is stored in the memory of the main control processing unit.

[0037] S1, Laser clamping Insert the laser under test into the top of the positioning cylinder and push it forward. The grippers, spring-loaded, hold the laser housing, and the flared guide structure guides the laser smoothly into place. Continue pushing until the laser's output face contacts the limiting block. At this point, the laser is in place, and the distance from the output port to the photosensitive surface of the CMOS image sensor is a fixed value. .

[0038] S2, Adaptive Exposure Control: The main control processing unit controls the CMOS image sensor to acquire a frame of image with initial parameters (low gain, short exposure), calculates the maximum gray value and average gray value of the image, and determines the current exposure state.

[0039] Exposure control employs a three-level linkage strategy: Level 1, Filter Switching: If the image is overexposed (maximum grayscale value close to the saturation threshold), the main control processing unit controls the electrically adjustable neutral density filter to switch to a higher attenuation ratio (e.g., from OD1 to OD2); if the image is too weak (average grayscale value below the preset lower limit), it switches to a lower attenuation ratio (e.g., from OD1 to the neutral density). After switching, the image is reacquired and evaluated.

[0040] Level 2, Exposure Time Adjustment: If the image is still overexposed after switching to the maximum attenuation level (such as OD3), the main control processing unit further reduces the exposure time of the CMOS image sensor, decreasing the current value by 10% each time, until the image grayscale is within a suitable range.

[0041] Level 3, Gain Adjustment: If the image is still too weak after switching to the minimum attenuation level (empty position), the main control processing unit further increases the exposure time and gain of the CMOS image sensor, increasing the current value by 10% each time, until the image grayscale is within a suitable range.

[0042] S3, Virtual Alignment Correction After the exposure parameters are set, the main control processing unit performs virtual alignment correction on the acquired spot image, which includes the following sub-steps: The first step is to calculate the gray-level centroid. Calculate the gray-level centroid coordinates of the original spot image using the following formula: in For the original spot image in pixels The grayscale value at that location.

[0043] The second step is virtual translation correction. This involves calculating the centroid. With image center offset , The original image is virtually translated so that its centroid is moved to the center of the image, resulting in the translated image: in The translated image in coordinates The grayscale value at that location.

[0044] in This is the image after vignetting correction. This is the pre-calibrated vignetting correction coefficient.

[0045] Step 4: Distortion correction. This involves correcting the vignetting in the image. Apply a pre-calibrated distortion correction mapping function to map each pixel from its original coordinates to its corrected coordinates: in This is the distortion correction mapping function. This is the offset for virtual translation. (The original image...) The grayscale value is assigned to the corrected coordinates. The virtual center spot image is obtained. .

[0046] S4. Simultaneous calculation of multiple parameters: The main control processing unit synchronously calculates the following five parameters on the virtual center spot image: Optical power calculation: Calculate optical power using the following formula. in The power conversion factor, The grayscale integral value of the virtual center spot image. The transmittance of an electrically adjustable neutral density filter. The distance from the centroid of the light spot to the center of the image. For about The monotonically increasing function is determined through pre-calibration.

[0047] Spot diameter calculation: The second-order moment method (D4σ) is used to calculate the spot diameter. in The effective area of ​​the light spot (the set of pixels whose grayscale value is greater than a preset threshold).

[0048] Divergence angle calculation: Calculate the divergence angle using the following formula. in , The diameter of the light spot on the virtual center spot image is directly measured using the second-order moment method. For about The monotonically decreasing function is determined through pre-calibration. This is the fixed distance from the positioning surface of the limit block to the photosensitive surface of the CMOS image sensor.

[0049] Ellipticity calculation: Calculate the ellipticity using the following formula. Beam spot uniformity calculation: Within the effective area of ​​the beam spot, the uniformity is calculated using the following formula. in The standard deviation of the gray values ​​within the light spot area. This represents the average of the grayscale values. The smaller the value, the more uniform the light spot.

[0050] S5. Output detection results The main control processing unit compares the calculated optical power, spot diameter, divergence angle, ellipticity, and spot uniformity parameters with preset thresholds to determine whether the performance of the laser under test is qualified, and outputs the test results to the display screen or host computer.

[0051] In batch testing scenarios, after testing one laser, the operator simply removes it and inserts the next laser to be tested. Because the repeatability of the elastic gripper is better than ±0.3 mm, and the spot eccentricity within ±2 mm can be effectively compensated by the virtual alignment correction algorithm, no mechanical alignment or calibration is required. The testing can be completed by simply repeating steps S1 to S5, reducing the single testing time to less than five seconds.

[0052] The following are parameters for a set of embodiments, but the present invention is not limited thereto: Positioning cylinder inner diameter: compatible with laser diameters ranging from φ8mm to φ12mm; Spring stiffness: The stiffness of each spring is approximately 5 N / mm; CMOS image sensor: Employs a global shutter type area array sensor with a photosensitive area size of 8.8mm × 6.6mm (2 / 3 inch), 5 million effective pixels, and a dynamic range of 70dB; Motorized adjustable neutral density filter: Four filters are installed on the rotating wheel, with transmittances of 100% (vacancy), 10% (OD1), 1% (OD2), and 0.1% (OD3). fixed distance The distance from the positioning surface of the limit block to the photosensitive surface of the CMOS image sensor is 100mm; Calibration eccentricity range: ±2mm; Detection accuracy: Within a ±2mm eccentricity range, the optical power measurement error is better than ±0.5%, and the spot diameter measurement error is better than ±0.02mm.

[0053] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A laser-assisted detection device, characterized in that, include: Mounting platform (1), mounting frame (4), laser fixing and bearing mechanism, single-module photoelectric detection component and main control processing unit (10). The mounting bracket (4) is connected to the mounting platform (1); The laser fixing support mechanism includes a positioning cylinder (6), a bracket (5) connected to the positioning cylinder (6), a mounting bracket (4) connected to the bracket (5), three or more sets of grippers (3) evenly distributed along the circumference of the inner wall of the positioning cylinder (6), a telescopic rod (11) connected to the gripper (3), the telescopic rod (11) connected to the inner wall of the positioning cylinder (6), a spring (13) sleeved on the outer side of the telescopic rod (11), the two ends of the spring (13) connected to the gripper (3) and the inner wall of the positioning cylinder (6) respectively, the gripper (3) connected to a limit block (12), the limit block (12) being used to abut against the light-emitting end face of the laser to be tested; The single-module photoelectric detection component includes an electrically adjustable neutral density filter (8) and a CMOS image sensor (9). The electrically adjustable neutral density filter (8) has multiple switchable levels with different attenuation ratios. The CMOS image sensor (9) is used to acquire light spot images and output grayscale data. The central axis of the positioning cylinder (6), the central axis of the filter in the working position of the electrically adjustable neutral density filter (8), and the central axis of the photosensitive surface of the CMOS image sensor (9) coincide; The main control processing unit (10) is electrically connected to the electrically adjustable neutral density filter (8) and the CMOS image sensor (9) respectively. The main control processing unit (10) is configured to: determine whether the image is overexposed based on the gray value of the image collected by the CMOS image sensor (9), and control the electrically adjustable neutral density filter (8) to switch gears; perform virtual alignment correction on the collected spot image, including calculating the centroid coordinates of the spot, virtually translating the image to move the centroid to the center of the image, and applying the pre-calibrated vignetting correction coefficient and distortion correction model; calculate the light power based on the gray integral of the virtually corrected image, and simultaneously calculate the spot diameter, divergence angle, ellipticity and spot uniformity parameters on the virtually corrected image; And output the detection results; The device does not contain any precision displacement stage, galvanometer, or mechanical adjustment mechanism for spot alignment.

2. The laser-assisted detection device as described in claim 1, characterized in that, Each of the springs (13) has the same stiffness, and the springs (13) in their natural state cause the inner diameter formed by the gripper (3) to be smaller than the minimum expected diameter of the laser under test.

3. The laser-assisted detection device as described in claim 1, characterized in that, The end of the gripper (3) away from the limiting block (12) opens outward in a flared shape to guide lasers of different diameters to be inserted smoothly.

4. The laser-assisted detection device as described in claim 1, characterized in that, The CMOS image sensor (9) is a global shutter type area array sensor with a rectangular photosensitive area. The long side dimension is not less than 12mm, the short side dimension is not less than 9mm, and the dynamic range is ≥70dB.

5. The laser-assisted detection device as described in claim 1, characterized in that, It also includes a light shield (2), which is a cylindrical structure with openings at the top and bottom. The light shield (2) is fitted with the mounting platform (1) and placed outside the mounting frame (4), the laser fixing and bearing mechanism, the single-module photoelectric detection component and the main control processing unit (10). The light shield (2) is provided with a cable outlet (7).

6. A laser detection method, based on the apparatus according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Insert the laser to be tested into the positioning cylinder (6), so that the gripper (3) clamps the laser housing under the action of the spring (13) until the laser output end face contacts the limiting block (12); S2. The main control processing unit (10) automatically controls the electric adjustable neutral density filter (8) to switch gears based on the gray value of the image collected by the CMOS image sensor (9) so that the image gray value is within a suitable range. S3. The main control processing unit (10) performs virtual alignment correction on the acquired spot image to correct the off-center spot to a virtual center spot image. S4. The main control processing unit (10) calculates the optical power based on the gray-scale integral of the virtual center spot image, and simultaneously calculates the spot diameter, divergence angle, ellipticity and spot uniformity parameters on the virtual center spot image. S5. Output the detection results.

7. The laser detection method as described in claim 6, characterized in that, The virtual alignment correction in step S3 includes: calculating the centroid position of the spot based on the grayscale distribution of the original spot image; virtually translating the original image so that the centroid of the spot moves to the center of the image; applying a pre-calibrated vignetting correction coefficient to perform pixel-by-pixel gain compensation on the translated image; and applying a pre-calibrated distortion correction mapping function to perform geometric correction on the image to obtain a virtual center spot image.

8. The laser detection method as described in claim 6, characterized in that, It also includes a pre-calibration step S0, which is performed before S1: S0. Use a uniform surface light source to perform vignetting calibration on the CMOS image sensor (9) and generate vignetting correction coefficients; use a checkerboard calibration plate to perform distortion calibration and solve the distortion correction mapping function; use a standard optical power meter to perform power calibration, establish the mapping relationship between grayscale integral value and actual power, and obtain the power conversion coefficient. The eccentricity correction coefficient was calibrated using a standard laser and a precision displacement stage, and the correction relationship between the eccentricity distance of the spot centroid and the power measurement error and diameter measurement error was established.

9. A laser detection method as described in claim 8, characterized in that, In step S4: optical power according to Calculation, where The power conversion factor, The grayscale integral value of the virtual center spot image. The transmittance of the electrically adjustable neutral density filter (8) The distance from the centroid of the light spot to the center of the image. For about The monotonically increasing function is determined by calibration in step S0. divergence angle Calculation, where , The diameter of the light spot measured on the virtual center light spot image. For about The monotonically decreasing function is determined through the calibration in step S0. The fixed distance between the positioning surface of the limiting block (12) and the photosensitive surface of the CMOS image sensor (9).

10. A laser detection method as described in claim 6, characterized in that, The step of making the image grayscale in step S2 includes: the main control processing unit (10) prioritizes controlling the switching position of the electrically adjustable neutral density filter (8); if the image is still overexposed after switching to the maximum attenuation position, the exposure time of the CMOS image sensor (9) is further reduced; if the image is still too weak after switching to the minimum attenuation position, the exposure time and gain of the CMOS image sensor (9) are further increased.

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