A low-cost high-resolution single-point scanning laser beam quality measuring device and method

Abstract

The application discloses a low-cost high-resolution single-point scanning laser beam quality measuring device and method, and relates to the technical field of laser beam quality measurement. The low-cost high-resolution single-point scanning laser beam quality measuring device comprises a focusing mirror, a light transmission plate and a single-tube detector; the light transmission plate is provided with a light transmission hole; and the focusing mirror, the light transmission hole and the single-tube detector are sequentially arranged along the light path propagation direction. The application realizes image collection of a non-visible light wave band laser spot, and further realizes measurement of laser beam quality; further, through the setting of an XY moving platform, the whole spot pattern of the laser beam can be acquired, the obtained image of the laser spot is not deformed, directly reflects the distribution of the laser spot intensity, and the accuracy of the image can be controlled through the selection of the XY moving platform accuracy; through the control of a magnifying glass and time sequence pulses in different directions, the subdivision collection of the spot is realized; and through simple and low-cost means, the collection of high-precision spots is realized.

Description

Technical Field

[0001] This invention relates to a low-cost, high-resolution single-point scanning laser beam quality measurement device and method, belonging to the field of non-visible light band laser beam quality measurement technology. Background Technology

[0002] like Figure 1 As shown, the light response spectrum of a commonly used CMOS camera shows that its cutoff wavelength in the long-wavelength direction is slightly greater than 1000nm (the cutoff position of the light response is set at 20%); the light response wavelength of a commonly used CCD camera is slightly longer than that of CMOS in the long-wavelength direction, but it also extends to slightly less than 1100nm; for lasers with wavelengths greater than 1000nm (for CMOS cameras) or 1080nm (for CCD cameras), commonly used silicon-based digital cameras cannot detect them.

[0003] like Figure 2 As shown, common M:YAG (M represents various doped metals) lasers have wavelengths greater than 1064nm. Mid-infrared lasers, which have been very active in recent years, and even infrared CO2 lasers with long wavelengths of 10.6µm, are mostly beyond the optical response band of silicon-based CMOS / CCD cameras, making it impossible to obtain digital images. Without obtaining digital images of the laser beam, it is impossible to quantitatively measure the quality of the laser beam, which is a technical problem that needs to be solved.

[0004] To address the aforementioned technical challenges, currently, acquiring images of short-wave infrared laser spots can be achieved using InGaAs-based near-infrared cameras, whose intrinsic spectral response covers the 1.7µm band and can even extend to 2.5µm. For mid-infrared laser spot images, InSb-based or MCT-based mid-infrared cameras (3µm-5µm) can be used. For long-wavelength laser spot detection, such as CO2 at 10.6µm, silicon-based microbolometer long-wavelength cameras can be employed. However, these short-wave, mid-wave, and long-wavelength infrared cameras are all very expensive, and their array size and resolution are far inferior to silicon-based CMOS cameras, making widespread adoption in industrial applications difficult.

[0005] There are also a few reports in the prior art that use photodetectors to analyze the quality of laser beams, such as the patent with the application number 201610215402.2, which discloses a fiber laser beam quality measurement method based on a photodetector and a CCD camera. This patent uses a CCD camera to collect the image of a laser beam, and is only suitable for the quality evaluation of visible light laser beams. Although this patent mentions using a photodetector, it only obtains the contour line of the light spot through a screw micrometer, and does not attempt to obtain the image of the laser beam light spot, nor does it involve the image of the invisible waveband laser light spot. The patent with the application number 201410665216.X discloses a pulsed laser beam quality synchronous measurement system and a synchronous control method. The photodetector in this patent is only used to obtain a trigger signal when a laser pulse appears, to inform the CCD camera to take a picture and obtain an image. However, the CCD camera cannot obtain the image of the invisible laser beam light spot, and the image acquisition method in this patent is completely different from the single-tube scanning method proposed in this application. The patent with the application number 200520044252.0 discloses a device for measuring the parallelism of a laser beam. This patent uses a 4-quadrant detector to obtain symmetry information of the light spot, and is not intended to obtain an image. It is quite different from this application and has no substantial comparability. SUMMARY

[0006] The present application provides a low-cost high-resolution single-point scanning laser beam quality measurement device and method, which realizes low-cost, high-resolution, and high-reliability acquisition and measurement of non-visible light waveband laser light spots, and is convenient for widespread promotion in industrial applications.

[0007] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0008] A low-cost high-resolution single-point scanning laser beam quality measurement device, comprising a focusing mirror, a light transmission plate, and a single-tube detector. The light transmission plate is provided with a light transmission hole, and the focusing mirror, the light transmission hole, and the single-tube detector are arranged in sequence along the light propagation direction.

[0009] Due to the unique frequency selection characteristics of laser itself, laser can only be stable at a specific wavelength, so the wavelength of laser radiation can only exist at some discrete wavelength positions. Similarly, the wavelength response of the detector also has a certain range, and it cannot be detected beyond the wavelength response range. Therefore, in order to measure the optical signal of the laser, a detector with appropriate response wavelength should be selected, and it is not necessary to be limited to silicon-based.

[0010] The wavelength of the laser beam beyond the imaging capability of the silicon-based CCD and CMOS camera detector may be in the ultraviolet waveband (short-wave side of the light response of silicon) or in the infrared waveband (long-wave side of the light response of silicon).

[0011] For a specific wavelength of laser, such as infrared laser, silicon-based CCD and CMOS cannot be used for imaging, but the single tube detector used in the application greatly reduces the cost of the sensor, and the technology is not limited to silicon-based CCD and CMOS area camera, and the corresponding single tube detector can be freely selected according to the wavelength of the laser. For example, in addition to bolometer detectors, quantum detectors, pyroelectric detectors, and even vacuum electron detectors can be used to detect all possible laser spots.

[0012] The application creatively provides an imaging method for obtaining a laser spot by a single tube scanning method. The single tube detector used in the application has low price and high freedom in selection.

[0013] Generally, the photosensitive surface of the single tube detector is relatively large, in the order of several millimeters; and the diameter of the laser spot is also several millimeters. Therefore, directly hitting the laser on the single tube detector can measure the light response of the single tube detector, but cannot obtain the image and intensity distribution of the laser spot. In order to obtain the image and intensity distribution of the laser spot by using the single tube detector, a light-transmitting small hole with a diameter of 2um to 20um is designed. The light-transmitting plate is installed upstream of the single tube detector or directly on the protective window of the single tube detector.

[0014] The diameter of the light-transmitting small hole cannot be made very small, which is not technically impossible, but when the diameter of the light-transmitting small hole is too small, the light flux hitting the photosensitive surface of the single tube detector through the light-transmitting small hole is too low, even lower than the detection threshold of the single tube detector, resulting in detection failure.

[0015] Taking the pixel size of a conventional silicon-based CMOS camera as a reference, for example, 3um to 5um, as the diameter of the light-transmitting small hole. Such selection of engineering parameters is in accordance with the principles of engineering design, which can be implemented, has reasonable performance, maintains low cost, or in other words, conforms to the principle of optimal cost performance.

[0016] Although the application aims to obtain a laser spot in the non-visible light band, it can also be applied to visible light band laser; at the same time, it is not limited to obtaining only the image of the laser spot, and can be applied to general image scanning imaging.

[0017] The measurement method of the above-mentioned low-cost high-resolution single-point scanning laser beam quality measurement device is as follows: the measured laser is focused by a focusing mirror, passes through a light-transmitting small hole, and is scanned and imaged by a single tube detector to obtain a digital image of the laser spot, and the parameters of the spot are quantitatively analyzed to realize quantitative measurement and evaluation of the infrared laser beam quality.

[0018] The quantitative analysis of the parameters of the light spot can be directly referred to the prior art, such as the size, ellipticity, intensity distribution, half-height width and other parameters related to the quality of the laser beam can be calculated to realize the detection and evaluation of the quality of the laser output.

[0019] In order to improve the resolution, the low-cost high-resolution single-point scanning laser beam quality measurement device described above further comprises an XY moving platform, and the single-tube detector is installed on the XY moving platform.

[0020] The diameter of the laser spot is usually several millimeters, and the diameter of the light transmission hole and the moving precision of the XY platform jointly define the pixel resolution of the obtained laser spot image.

[0021] The XY moving platform with a positioning accuracy of 5 um or more is relatively low in price; as the positioning accuracy decreases from 5 um to 1 um, the price of the XY moving platform also gradually increases. The cost of the device can be controlled by selecting XY platforms with different positioning accuracies.

[0022] During measurement, the single-tube detector is placed at the focal plane of the laser to be measured. Assuming that the diameter of the light transmission hole is 5 um and that the XY moving platform moves 5 um to collect a light response data from the single-tube detector. When the single-tube detector scans the entire focal plane of the laser along with the XY platform step by step, a digital image of the laser spot is obtained. Since the XY is a linear moving platform, the obtained image of the laser spot is not deformed, directly reflecting the distribution of the intensity of the laser spot.

[0023] For example, when the diameter of the light transmission hole is 5 um, if the XY platform with a positioning accuracy of 5 um is selected, the resolution of the image is basically the same as that of the CMOS camera, but higher than that of the infrared camera, and the cost is much lower than that of the infrared camera.

[0024] The pixel size of the mainstream infrared camera is about 15 um, for example, the diameter of the light transmission hole is selected to be 15 um, and the positioning accuracy of the XY platform can be selected to be 10 um, so that the resolution of the collected laser spot image is basically the same as that of the mainstream infrared camera, but the cost is greatly reduced.

[0025] If the scanning is along a circular arc, it is not linear and will introduce large errors in subsequent data processing. In the present application, the light transmission plate is installed on the protective window of the single-tube detector, which not only avoids the large errors caused by circular arc scanning, but also has high energy sampling efficiency and higher resolution compared with the sampling hole on the rotating flat plate.

[0026] The XY moving platform is arranged, and when measuring, the single-tube detector is placed at the focal plane of the laser to be measured, and the single-tube detector is driven by the XY moving platform to gradually scan the entire focal plane of the laser to be measured, so that the laser spot is obtained.

[0027] The scanning imaging technology of the infrared laser spot in the application is not only cheaper than the infrared camera, but also can measure a large spot with a laser spot diameter larger than the target surface of the infrared camera, which cannot be realized by the infrared camera.

[0028] The XY moving platform is arranged, and when measuring, the single-tube detector is placed at the focal plane of the laser to be measured, and the single-tube detector is driven by the XY moving platform to gradually scan the entire focal plane of the laser to be measured, so that the laser spot is obtained.

[0029] As one of the implementation schemes, in order to further improve the accuracy of the laser spot image acquisition, the low-cost high-resolution single-point scanning laser beam quality measurement device further comprises a magnifying lens, a focusing lens, a magnifying lens, a light transmission aperture and a single-tube detector arranged in sequence along the light path propagation direction.

[0030] For example, the diameter of the light transmission aperture is maintained at 15 um, and the positioning accuracy of the XY moving platform is also maintained at 10 um. At this time, by magnifying the laser spot, the subdivision acquisition of the entire laser spot is improved, and more pixels are used to represent the entire laser spot, thereby improving the accuracy of the spot detection.

[0031] The above-mentioned laser spot magnification realizes higher spatial subdivision image of the laser spot. As common sense, the spatial division of the infrared laser spot by the infrared camera is determined by the pixel area of the camera, for example, 17umX17um. Once the infrared camera is selected, the number of pixels of a laser spot is determined.

[0032] The above-mentioned magnifying lens is arranged, and when measuring, the laser to be measured passes through the focusing lens, the magnifying lens and the light transmission aperture in sequence, and then is scanned and imaged by the single-tube detector to obtain the laser spot. By magnifying the laser spot, the subdivision acquisition of the entire laser spot is improved, and more pixels are used to represent the entire laser spot, thereby improving the accuracy of the spot detection.

[0033] In addition to the above-mentioned magnification of the laser spot before detection to improve the number of spot spaces, as another implementation scheme, further, an electric control method can be used to further realize the spatial subdivision of the spot.

[0034] As one of the implementation schemes of the electric control, the higher spatial subdivision collection of the laser spot in the X or Y direction is realized by controlling the X or Y direction collection timing pulse, and the specific steps include:

[0035] a. The XY moving platform drives the single tube detector to move to yi or xi position in the Y or X direction;

[0036] b. The pulse generator is used to give the uniform pulse to the X or Y direction driving motor, so that the single tube detector moves uniformly in the X or Y direction;

[0037] c. When the single tube detector moves to the area of the laser spot, the single tube detector is opened, and the light intensity response of different positions of the spot is periodically collected; the speed of the uniform motion of the single tube detector is adjusted, and the frequency of collecting data from the single tube detector is adjusted, so as to realize the adjustment of the resolution of the spot image.

[0038] In step b, the linear motor can also be directly used to drive the single tube detector to move uniformly in the X or Y direction.

[0039] By using the above scheme, even if the positioning accuracy of the X or Y moving platform is poor, as long as the uniform motion can be realized, the high resolution imaging of the spot can be realized.

[0040] As another implementation scheme of the electric control, the higher spatial subdivision image collection in the two-dimensional direction of the laser spot is realized by controlling the X and Y direction collection timing pulse, and the specific steps include:

[0041] a. The pulse generator is used to give the uniform pulse to the X and Y direction driving motor, so that the single tube detector moves uniformly in the X and Y direction;

[0042] b. When the single tube detector moves to the area of the laser spot, the single tube detector is opened, and the light intensity response of different positions of the spot is periodically collected; the speed of the uniform motion of the single tube detector is adjusted, and the frequency of collecting data from the single tube detector is adjusted, so as to realize the adjustment of the resolution of the spot image.

[0043] In step a, as long as the X and Y axes form uniform motion, therefore, the single tube detector also moves uniformly in the combined motion direction of the X and Y axes. By controlling the motion pulse of the X and Y axes, the single tube detector can realize the high resolution two-dimensional imaging of the laser spot.

[0044] Using a dedicated infrared camera to acquire images of laser beam spots is too expensive and difficult to widely promote in industrial applications. This application uses a single-tube detector that can respond to the corresponding laser band (which can be directly selected from existing commercially available products). Through the development of the above-mentioned optical, mechanical and electronic control schemes, it realizes the image acquisition of laser spots in the non-visible light band. After the image is acquired, various parameters of the laser spot can be quantitatively analyzed using existing methods, so as to realize the quantitative measurement and evaluation of the laser beam quality.

[0045] Of course, this application is also applicable to the image acquisition of laser spots in the visible light band, but the image acquisition of laser spots in the visible light band can also be directly obtained using inexpensive CMOS and CCD.

[0046] Any techniques not mentioned in this invention are based on existing technologies.

[0047] This invention provides a low-cost, high-resolution single-point scanning laser beam quality measurement device. It enables image acquisition of laser beam spots in the non-visible light band, thereby measuring the laser beam quality. Furthermore, by setting up an XY motion platform, the entire laser beam pattern can be acquired. The resulting laser beam image is undistorted and directly reflects the intensity distribution of the laser beam. Simultaneously, the image accuracy can be controlled by selecting the precision of the XY motion platform. Through the control of a magnifying glass and timing pulses in different directions, the beam spot can be subdivided for acquisition. High-precision beam spot acquisition is achieved using simple and low-cost methods. Attached Figure Description

[0048] Figure 1 This is the spectral response spectrum of a common CMOS / CCD camera;

[0049] Figure 2 This is a wavelength distribution diagram of common laser light sources;

[0050] Figure 3 This is the optical path diagram of the low-cost, high-resolution single-point scanning laser beam quality measurement device in Example 1;

[0051] Figure 4 This is a schematic diagram of the light-transmitting plate structure of the present invention;

[0052] Figure 5 This is the optical path diagram of the low-cost, high-resolution single-point scanning laser beam quality measurement device in Example 2;

[0053] Figure 6 The laser spot pattern obtained in Example 2;

[0054] Figure 7 This is the optical path diagram of the low-cost, high-resolution single-point scanning laser beam quality measurement device in Example 3;

[0055] Figure 8 This is the timing pulse control diagram in the X direction of Example 4;

[0056] Figure 9 This is the timing pulse control diagram for the X and Y directions in Example 5;

[0057] In the figure, 1 is a focusing lens, 2 is a light-transmitting plate, 21 is a light-transmitting aperture, 3 is a single-tube detector, 4 is the infrared laser under test, 5 is an XY moving platform, and 6 is a magnifying glass. Detailed Implementation

[0058] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0059] Example 1

[0060] like Figure 3 As shown, a low-cost, high-resolution single-point scanning laser beam quality measurement device includes a focusing lens, a light-transmitting plate, and a single-tube detector; Figure 4 As shown, a light-transmitting hole with a diameter of 2um to 20um is provided on the light-transmitting plate, and the focusing lens, the light-transmitting hole and the single tube detector are arranged in sequence along the light path propagation direction; the light-transmitting plate is installed on the protective window of the single tube detector.

[0061] Due to the inherent frequency selectivity of lasers, they can only emit laser light stably at specific wavelengths. Detectors also have a limited wavelength response range. Therefore, to measure laser light signals, a detector with a suitable response wavelength must be selected, rather than being limited to silicon-based detectors. Furthermore, the appropriate single-tube detector can be freely selected based on the laser's wavelength. Taking infrared laser detection as an example, in addition to calorimeter detectors, quantum detectors, pyroelectric detectors, or even vacuum electronic detectors can be used.

[0062] The wavelengths of laser beams that exceed the detection and imaging capabilities of silicon-based CCD and CMOS cameras may be in the ultraviolet band (the short-wavelength side of silicon's photoresponse) or the infrared band (the long-wavelength side of silicon's photoresponse). For lasers of specific wavelengths, such as infrared lasers, silicon-based CCDs and CMOS cameras cannot detect and image them. However, the use of single-tube detectors greatly reduces the cost of sensors, and technically, it is no longer necessary to be limited to silicon-based CCD and CMOS area array cameras.

[0063] The method for measuring laser beam quality using the above-mentioned device, such as Figure 3As shown, the to-be-tested laser is focused by a focusing mirror, passes through the light-transmitting aperture, is scanned by the single-tube detector to form an image, and a digital image of the laser spot is obtained. The parameters of the laser spot are quantitatively analyzed, and quantitative measurement and evaluation of the quality of the infrared laser beam are realized. The quantitative analysis of the parameters of the laser spot can be directly referred to the prior art. For example, the size, ellipticity, intensity distribution, half-height width, and other parameters related to the quality of the laser beam can be calculated to realize detection and evaluation of the quality of the laser output.

[0064] Embodiment 2

[0065] Based on the embodiment 1, the following improvements are made: Figure 5 As shown, the low-cost high-resolution single-point scanning laser beam quality measurement device further comprises an XY moving platform, and the single-tube detector is installed on the XY moving platform.

[0066] The diameter of the light-transmitting aperture and the moving precision of the XY platform jointly define the pixel resolution of the obtained laser spot image. During measurement, the single-tube detector is placed at the focal plane of the to-be-tested laser. In this example, the diameter of the light-transmitting aperture is 5 um, and the XY moving platform moves by 5 um each time to collect a light response data from the single-tube detector. When the single-tube detector scans the entire focal plane of the laser along with the XY platform step by step, a digital image of the laser spot is obtained, as shown. Figure 6 Since the XY platform is a linear moving platform, the obtained image of the laser spot is not deformed, and directly reflects the intensity distribution of the laser spot. The above device can measure a large laser spot with a diameter larger than the target surface of the infrared camera, which cannot be achieved by the infrared camera.

[0067] The diameter of the light-transmitting aperture is 5 um, and the positioning precision of the XY platform is 5 um. The resolution of the image is basically the same as that of the CMOS camera, but higher than that of the infrared camera. However, the cost is much lower than that of the infrared camera. When the diameter of the light-transmitting aperture is selected as 15 um, and the positioning precision of the XY platform is selected as 10 um, the resolution of the collected image of the laser spot is basically the same as that of the mainstream infrared camera, but the cost is greatly reduced.

[0068] The method for measuring the quality of the laser beam by using the above device is as shown: Figure 5 The single-tube detector is placed at the focal plane of the to-be-tested laser, and is driven by the XY moving platform to scan the entire focal plane of the to-be-tested laser step by step. The laser spot as shown is obtained. Figure 6 The size, ellipticity, intensity distribution, half-height width, and other parameters related to the quality of the laser beam are calculated to realize detection and evaluation of the quality of the laser output.

[0069] Embodiment 3

[0070] On the basis of embodiment 2, the following improvements are further made: as shown in Figure 7 In order to further improve the accuracy of laser spot image acquisition, a magnifying lens, a focusing lens, a magnifying lens, a light transmission hole and a single tube detector are sequentially arranged along the light path propagation direction.

[0071] In this example, the diameter of the light transmission hole is 15 um, and the positioning accuracy of the XY moving platform is 10 um. At this time, by magnifying the laser spot, the subdivision collection of the entire laser spot is improved, and more pixels are used to represent the entire laser spot, thereby improving the accuracy of spot detection.

[0072] The method for measuring the quality of a laser beam by using the above device is as shown in Figure 7 After the laser to be measured sequentially passes through the focusing lens, the magnifying lens and the light transmission hole, it is scanned and imaged by the single tube detector to obtain a laser spot. By magnifying the laser spot, the subdivision collection of the entire laser spot is improved, and more pixels are used to represent the entire laser spot, thereby improving the accuracy of spot detection.

[0073] Embodiment 4

[0074] On the basis of embodiment 3, the following improvements are further made: in addition to the laser spot being magnified and then detected in embodiment 3 to improve the number of spot spaces, in this example, an electric control method is combined to further realize the spatial subdivision of the spot. As shown in Figure 8 By controlling the X-direction acquisition timing pulse, higher spatial subdivision collection of the laser spot in the X-direction is realized, including the following steps:

[0075] a. The XY moving platform drives the single tube detector to move to yi position in the Y direction;

[0076] b. The pulse generator is used to input uniform pulses to the X-direction driving motor to make the single tube detector move at a constant speed in the X direction;

[0077] c. When the single tube detector moves to the region of the laser spot, the single tube detector is turned on to periodically collect the light intensity response of different positions of the spot; the speed of the uniform motion of the single tube detector is adjusted, and the frequency of data collection from the single tube detector is adjusted to realize the adjustment of the resolution of the spot image.

[0078] By using the above scheme, even if the positioning accuracy of the X moving platform is poor, as long as uniform motion can be realized, high-resolution imaging of the spot can be realized.

[0079] Embodiment 5

[0080] On the basis of embodiment 4, the following improvements are further made: as shown in Figure 9As shown, by controlling the X and Y direction acquisition timing pulse to realize higher spatial subdivision image acquisition in the two-dimensional direction of the laser spot, the XY scan obtains the entire subdivision image, and the steps are as follows:

[0081] a. Use the pulse generator to give the X and Y direction driving motor uniform pulse, so that the single tube detector moves at a constant speed in the X and Y direction; for example Figure 9 As shown, as long as the X and Y axes form a uniform motion, the single tube detector in the combined motion direction of X and Y is also a uniform motion;

[0082] b. When the single tube detector moves to the area of the laser spot, turn on the single tube detector, periodically collect the light intensity response of different positions of the spot; adjust the speed of the uniform motion of the single tube detector, and adjust the frequency of collecting data from the single tube detector, to realize the adjustment of the resolution of the spot image.

[0083] The above-mentioned by controlling the motion pulse of X and Y axes can make Figure 9 The oblique solid line in the above-mentioned can scan along the X direction to the right, so that the single tube detector can realize high-resolution two-dimensional imaging of the laser spot.

Claims

1. A low-cost high-resolution single-point scanning laser beam quality measurement method, characterized in that: a low-cost high-resolution single-point scanning laser beam quality measurement device used for measurement comprises a focusing mirror, a magnifying lens, a light transmission plate, a single-tube detector, an XY moving platform and a pulse generator; the light transmission plate is provided with a light transmission aperture; the focusing mirror, the magnifying lens, the light transmission aperture and the single-tube detector are sequentially arranged along the light propagation direction; the single-tube detector is installed on the XY moving platform; the pulse generator is connected with a driving motor in the X or / and Y direction of the XY moving platform; the low-cost high-resolution single-point scanning laser beam quality measurement method is as follows: after the to-be-measured laser is focused by the focusing mirror, the laser passes through the light transmission aperture and is scanned and imaged by the single-tube detector to obtain a digital image of a laser spot, various parameters of the laser spot are quantitatively analyzed, and quantitative measurement and evaluation of the infrared laser beam quality are realized; the single-tube detector is placed at a focal plane of the to-be-measured laser, and under the driving of the XY moving platform, the single-tube detector gradually scans the entire focal plane of the to-be-measured laser to obtain a laser spot; after the to-be-measured laser sequentially passes through the focusing mirror, the magnifying lens and the light transmission aperture, the laser is scanned and imaged by the single-tube detector to obtain a laser spot, the laser spot is magnified by the magnifying lens, the entire laser spot is subdivided and collected, more pixels are used to represent the entire laser spot, and the precision of the spot detection is improved; and / or, the subdivided collection of the laser spot in the X or Y direction is realized by controlling the X or Y direction acquisition timing pulse, including the following steps: a. the XY moving platform drives the single-tube detector to move to yi or xi position in the Y or X direction; b. the pulse generator is used to punch in uniform pulses for the driving motor in the X or Y direction, so that the single-tube detector moves uniformly in the X or Y direction; c. when the single-tube detector moves to the region of the laser spot, the single-tube detector is turned on, and the light intensity response of different positions of the spot is periodically collected; the speed of the uniform movement of the single-tube detector is adjusted, and the frequency of the data collection of the single-tube detector is adjusted to realize the adjustment of the resolution of the spot image. The light transmission plate is installed on the protective window of the single-tube detector; the diameter of the light transmission aperture is 2um-20um.

2. The low cost high resolution single point scanning laser beam quality measurement method of claim 1, wherein: The subdivided image collection of the laser spot in the two-dimensional direction is realized by controlling the X and Y direction acquisition timing pulse, including the following steps:

3. The low cost high resolution single point scanning laser beam quality measurement method according to claim 1 or 2, characterized in that: a. the pulse generator is used to punch in uniform pulses for the driving motor in the X and Y directions, so that the single-tube detector moves uniformly in the X and Y directions; b. when the single-tube detector moves to the region of the laser spot, the single-tube detector is turned on, and the light intensity response of different positions of the spot is periodically collected; the speed of the uniform movement of the single-tube detector is adjusted, and the frequency of the data collection of the single-tube detector is adjusted to realize the adjustment of the resolution of the spot image. ​

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