A high-power laser power meter calibration method and calibration device

Abstract

The present invention discloses a calibration method and a calibration device for a high-power laser power meter. The calibration method for the high-power laser power meter combines two or more low-power lasers with the same power and superimposes them on a standard power meter or the power meter to be calibrated, thereby realizing the calibration of the power meter to be calibrated. Among the low-power lasers, one is a central laser beam and the rest are peripheral laser beams, and the angle between the peripheral laser beams and the central laser beam after beam combination and superposition is less than 5°. The present invention realizes the calibration of a high-power laser power meter using low-power lasers, with high accuracy, good stability, easy operation, and high safety.

Description

Technical Field

[0001] The present invention relates to a calibration method and a calibration device for a high-power laser power meter, and belongs to the technical field of high-power laser power meter calibration. Background Art

[0002] Fiber lasers with kilowatt output have been mass-produced and widely used in industries such as cutting, welding, drilling, marking, cleaning, foreign object removal, and anti-drone. In practical applications, accurately measuring the output power of a laser is crucial for ensuring the normal function of laser processing equipment. If the laser output power is too low, it will cause the failure of the equipment's function; if the laser output power is too high, there will be a risk of burning out the equipment itself and the workpiece being processed. The laser output power is usually measured by a laser power meter. As the components of the laser power meter age, the readings of the laser power meter may drift and become inaccurate. To ensure that the laser power measurement value is accurate and reliable, it is necessary to calibrate the laser power meter regularly. This requires designing and manufacturing equipment that can calibrate a kilowatt-level laser power meter.

[0003] However, what can generate kilowatt-level laser output is usually a fiber laser, and the numerical value of its output power, the stability of its output power, and the stability of the polarization state of the output laser are not suitable for directly calibrating a kilowatt-level laser power meter accurately.

[0004] Therefore, it is necessary to propose a new set of principles and methods to achieve the calibration of a kilowatt-level laser power meter in engineering applications and meet the accuracy requirements of commercially available mainstream laser power meters. Summary of the Invention

[0005] The present invention provides a calibration method and a calibration device for a high-power laser power meter, which realizes the calibration of a high-power laser power meter using low-power lasers, has high accuracy, good stability, is easy to operate, and has high safety.

[0006] To solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0007] A calibration method for a high-power laser power meter combines two or more low-power lasers with the same power and superimposes them on a standard power meter or the power meter to be calibrated, thereby realizing the calibration of the power meter to be calibrated; among the low-power lasers, one is a central laser beam and the rest are peripheral laser beams, and the angle between the peripheral laser beams and the central laser beam after combination and superposition is less than 5°.

[0008] The above method is suitable for calibrating a high-power laser power meter.

[0009] This application uses the superposition irradiation of multiple beams of incoherent lasers to achieve high-power irradiation. For multiple beams of light, I1, I2, I3..., the illuminance generated when they irradiate a point is the direct addition of all beams of light. If the spot sizes of multiple lasers are the same and they irradiate the same point on the target at an angle close to perpendicular, then the irradiation effect is the same as that of a high-power laser with the same power after addition.

[0010] The applicant found through research that if the laser beam output from a kilowatt-class fiber laser is directly hit on a standard laser power meter and then on a calibrated laser power meter, and the reading of the calibrated laser power meter is projected onto the standard laser power meter by comparing the readings of the two to perform the calibration operation of the calibrated laser power meter, the following problems exist: The quality of the laser beam output from the kilowatt-class fiber laser is very low, and the power stability and the stability of the polarization state of the output laser are not sufficient to meet the accuracy requirements of the instrument level. For example, for a laser power meter with an accuracy of 1%, the requirement for the stability of the laser power should reach 0.1%, but in fact, such a laser supply cannot be found. Currently, on the market, the output power of the fiber laser with better beam output characteristics that can be found is only 500W, and the polarization state can only reach >50:1, so there is a 2% uncertainty. Directly using a kilowatt-class laser with poor output characteristics and a 500W-class fiber laser with better output characteristics cannot achieve the measurement and calibration operations of the kilowatt-class laser power meter. Due to the lack of a fiber laser with a kilowatt-class output of instrument-level quality, the highest output power of the fiber laser with the highest output quality that can be found currently is only 500W. This so-called highest laser output quality only reaches an extinction ratio of 50:1 and still does not meet the requirements of the instrument-level light source.

[0011] To improve the calibration accuracy, all low-power lasers pass through an expander and a polarizer in sequence, and then are combined and superimposed on the standard power meter or the calibrated power meter.

[0012] Expand each beam of low-power laser to make the diameter of the laser beam larger, reduce the power density per unit area, prevent the burning of optical components, and facilitate subsequent operations. Because the expander is axisymmetric and the laser beam is also axisymmetric, as long as the installation accuracy is sufficient, beam expansion will not cause a decrease in the parameter quality of the laser beam.

[0013] After beam expansion, it first passes through a polarizer. The purpose is to improve the polarization characteristics of the original laser output. Taking the laser with an output of 500W as an example, after beam expansion, a polarizer is first installed. The purpose is to improve the polarization characteristics of the original laser output from 50:1 to 1000:1 or even 10000:1, that is, to improve the polarization characteristics of the laser beam from the industrial level to the instrument level, greatly suppressing the uncertainty of the polarization state.

[0014] To further improve the accuracy and stability of calibration, the above-mentioned high-power laser power meter calibration method includes the following steps in sequence:

[0015] 1) After each low-power laser passes through a beam expander and a polarizer in sequence, sample using a laser sampler and measure the power of the sampled sample using a laser sampling power meter. The power readings of each low-power laser at time t are I1(t), I2(t), I3(t), …… respectively. The total power Is(t) of each low-power laser at time t is also a function of time, and Is(t) = I1(t) + I2(t) + I3(t) + ……;

[0016] 2) Combine and superimpose all low-power lasers on a standard power meter. The reading of the standard power meter at time t is Ia(t); each laser sampling power meter and the standard power meter need to collect readings simultaneously. Through the readings at different times, establish a one-to-one corresponding functional relationship between Ia(t) and Is(t);

[0017] 3) Combine and superimpose all low-power lasers on the power meter to be calibrated. Simultaneously collect the total reading Is(t) of each laser sampling power meter at time t and the reading Ia’(t) on the power meter to be calibrated. Using Is(t) as a bridge, through the one-to-one corresponding functional relationship between Ia(t) and Is(t) obtained in step 2), the corresponding Ia(t) of Ia’(t) can be obtained, thereby realizing calibration.

[0018] The above-mentioned laser sampling power meter and standard power meter have been calibrated by the national authoritative metrology department, and the readings are considered to be credible and accurate.

[0019] To suppress the uncertainty of laser power output, the solution proposes to adopt a method of collecting data in multiple channels and simultaneously, so that the collected data are all obtained under the same laser output conditions, and the collected data are no longer affected by the fluctuation of the laser output power. Therefore, the fluctuation of the laser output power can no longer affect the accuracy of the calibration equipment.

[0020] When collecting and measuring data as described above, each laser sampling power meter and the high-power standard power meter at the confluence of multiple beams of light must collect readings simultaneously. Since laser travels at the speed of light, no matter how the laser power output from the laser fluctuates, the laser power output at a certain time point t is always a definite value. Using the data collected by each sampling power meter and the high-power standard power meter, a one-to-one corresponding functional relationship between Ia(t) and Is(t) can be established, that is, knowing an Ia value is equivalent to knowing the corresponding Is value, and vice versa.

[0021] After establishing a one-to-one functional relationship between \(I_a(t)\) and \(I_s(t)\), on a two-dimensional graph with \(I_s(t)\) and \(I_a(t)\) as the coordinate axes, \(I_s(t)\) and \(I_a(t)\) are completely equivalent. After this relationship is established, the calibration operation of the power meter can be started.

[0022] Although after passing through the polarizer, the accuracy of the polarization characteristics of the laser has been improved to 0.1%, or even 0.01%, however, due to the output characteristics of the laser itself, the stability of the modified laser power is still 2%, which still fails to meet the requirements of the instrument level. The above steps eliminate the measurement uncertainty caused by the laser power fluctuation by simultaneously collecting data, that is, an instrument-level measurement independent of the laser power fluctuation is achieved.

[0023] To improve the calibration efficiency and at the same time improve the safety of the operation, a reflective light valve and a light absorber are provided downstream of each laser sampler. The reflective light valve can reflect the corresponding laser to the light absorber and all of it is collected by the light absorber. In this way, when replacing the standard power meter and the power meter to be calibrated during the operation, it is not necessary to turn off the low-power laser. As long as the corresponding laser is reflected to the light absorber for absorption by controlling the reflective light valve, the time waste from the laser being turned on to being stable is avoided, and at the same time, the safety of the operation on the subsequent optical path is protected.

[0024] To facilitate easily finding the accurate position when replacing the power meter and at the same time ensure the safety of the operation, a beam combiner is provided between the reflective light valve and the mirror. The optical path of the beam combiner coincides with the optical path of its corresponding low-power laser to indicate the position of its corresponding low-power laser on the standard power meter and the power meter to be calibrated, so as to determine the positions of the standard power meter and the power meter to be calibrated. The beam combiner is set to load a low-power visible laser for indication, so that the optical path of the visible laser completely coincides with the optical path of its corresponding infrared laser (low-power laser), that is, the low-power visible laser has the same pointing and the position where it falls on the power meter as its corresponding low-power laser. When replacing the power meter, the position of the power meter can be first determined by using the low-power visible laser, which facilitates easily finding the accurate position when replacing the power meter, improves the safety of the operation, and prevents the infrared laser from harming the operator.

[0025] To further improve the calibration accuracy, the angle between the peripheral laser beam and the central laser beam is less than 1.5°; the central laser beam is perpendicular to the surfaces of both the standard power meter and the power meter to be calibrated. Since the angle between other laser beams and the central laser beam is relatively small, other laser beams are also basically perpendicular to the surface of the power meter.

[0026] The above method is applicable to the calibration of kilowatt-level laser power meters.

[0027] To further improve the calibration accuracy, the spot produced on the surface of the standard power meter and the power meter to be calibrated after the combination and superposition of all low-power lasers coincides with the spot when only the central laser beam is present by more than 95%. That is, the spot produced on the power meter surface after the combination and superposition is basically the same as the spot when only the central laser beam is present. Namely, the spot after the combination and superposition of low-power lasers should be basically the same as the spot irradiated by a single low-power laser beam to avoid uncontrollable factors on the power meter. For example Figure 2 As shown, the structure of the laser power meter is several concentric circles, and the laser is vertically irradiated at the center, serving as a heat source. The heat diffuses from the center to the surroundings until it reaches the array sensors arranged in concentric circles, and the signal generated by the temperature difference is collected, which is the laser power value. The reason for requiring the spot formed by the superposition of multiple beams of light to be the same as the spot of a single laser beam with the same power is to ensure that the heat conduction conditions on the power meter are exactly the same, so as to guarantee the equivalence between the superposed multiple beams of lasers and a single laser beam with the same power.

[0028] A high-power laser power meter calibration device includes a standard power meter, a power meter to be calibrated, and a low-power laser optical path;

[0029] There are more than two low-power laser optical paths. One of the low-power laser optical paths is the central laser optical path, and the rest are peripheral laser optical paths. All low-power laser optical paths are combined and superposed on the standard power meter or the power meter to be calibrated. After the combination and superposition, the angle between the peripheral laser beam and the central laser beam is less than 5°.

[0030] The structures of all the above-mentioned low-power laser optical paths are the same. Along the propagation direction of the optical path, each low-power laser optical path includes a laser, a beam expander, a polarizer, and a reflector connected in sequence.

[0031] To facilitate sampling and simultaneously realize the measurement of the sampled samples, each low-power laser optical path is provided with a laser sampler and a laser sampling power meter. The laser sampler is arranged between the polarizer and the reflector, and the laser sampling power meter is used to measure the power of the samples collected by the laser sampler. That is, after the polarizer of each laser beam, a sampler is installed to extract a small part of the light to the sampling power meter.

[0032] To improve the calibration efficiency and simultaneously improve the safety of the operation, a reflective light valve and a light absorber are provided between each laser sampler and the reflector. The reflective light valve can reflect the corresponding optical path to the light absorber.

[0033] In order to easily find the accurate position when replacing the power meter, a beam combiner is provided between the reflective light valve and the mirror. The optical path of the beam combiner coincides with the optical path of its corresponding low-power laser to indicate the positions of its corresponding low-power laser on the standard power meter and the power meter to be calibrated, thereby determining the positions of the standard power meter and the power meter to be calibrated. The beam combiner is set to load a low-power visible laser so that the optical path of the visible laser completely coincides with the optical path of its corresponding infrared laser (low-power laser), that is, the pointing and the position where the low-power visible laser and its corresponding low-power laser fall on the power meter are the same. When replacing the power meter, the position of the power meter can be determined first by using the low-power visible laser, which makes it easy to find the accurate position when replacing the power meter, improves the safety of operation, and prevents the infrared laser from harming the operator.

[0034] In order to further improve the calibration accuracy, after beam combination and superposition, the angle between the peripheral laser beam and the central laser beam is less than 1.5°.

[0035] For the technologies not mentioned in the present invention, reference is made to the prior art.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1) Under the hardware condition of not having a shared kilowatt-level high-power laser, the method of superposing multiple low-power lasers is selected to complete the calibration target of the kilowatt-level high-power laser power meter, and the designed and manufactured calibration equipment has high precision, far higher than the measurement precision of the commonly used power meters on the market;

[0038] 2) In order to make the superposed laser beams from multiple beams consistent with a single-beam kilowatt-level high-power laser in terms of overall effect, this application ensures that all the beams are superposed on the surface of the power meter in a configuration almost perpendicular to the power meter as much as possible, and ensures that the light spot is basically the same as that of the high-power laser;

[0039] 3) In order to suppress the uncertainty of the polarization characteristics of the power laser, this application further adopts a polarizer with an extremely high extinction ratio. For example, the extinction ratio of 50:1 can be increased to 1000:1, or even 10000:1, and the polarization stability of the working laser is high, which lays a foundation for achieving high precision of the calibration equipment;

[0040] 4) In order to suppress the uncertainty of the laser power output, this application further adopts the method of simultaneously collecting data from multiple channels, so that the collected data are all obtained under the same laser output conditions, and the collected data are no longer affected by the laser output power fluctuation;

[0041] 5) Further through the setting of the sampling power meter, a one-to-one correspondence relationship is established between the readings of the standard power meter and the readings of the customer power meter to be calibrated, and the calibration of the customer power meter is achieved by fitting the calibration curve.

[0042] 6) Further, by adopting a reflective light valve, it is not necessary to turn off the laser during the calibration operation, eliminating the time for the laser to stabilize when it is turned on, improving the working efficiency of the calibration equipment, and also enhancing the safety of the equipment;

[0043] 7) The addition of the indicating laser provides convenience in operation for the calibration of the power meter for invisible laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic structural diagram of the high-power laser power meter calibration device of the present invention;

[0045] Figure 2 It is a schematic diagram of the principle of the high-power laser power meter;

[0046] In the figure, 1 is a laser beam (polarization state > 50:1), 2 is a beam expander, 3 is a polarizer, 4 is a laser sampler, 5 is a laser sampling power meter, 6 is a reflective light valve, 7 is a light absorber, 8 is a beam combiner, 9 is an indicating laser, 10 is a reflector, 11 is a standard power meter, 12 is the power meter to be calibrated, 13 is a temperature difference sensing unit, and 14 is a laser heating point. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments only.

[0048] Embodiment 1

[0049] As Figure 1 shown, a high-power laser power meter calibration device includes a standard power meter, a power meter to be calibrated, and a low-power laser optical path; there are three low-power laser optical paths, one of which is a central laser optical path and the rest are peripheral laser optical paths. All the low-power laser optical paths are combined and superimposed on the standard power meter or the power meter to be calibrated. After the combination and superposition, the included angle between the peripheral laser beam and the central laser beam is less than 5°.

[0050] Embodiment 2

[0051] On the basis of Embodiment 1, the following further improvements are made: all the low-power laser optical path structures are the same. Along the propagation direction of the optical path, each low-power laser optical path includes a laser (500W), a beam expander, a polarizer, and a reflector connected in sequence.

[0052] Embodiment 3

[0053] On the basis of Embodiment 2, the following further improvements are made: A laser sampler and a laser sampling power meter are provided on each low-power laser optical path. The laser sampler is arranged between the polarizing mirrors, and the laser sampling power meter is used to measure the power of the sample collected by the laser sampler.

[0054] Embodiment 4

[0055] On the basis of Embodiment 3, the following further improvements are made: A reflective light valve and a light absorber are provided between each laser sampler and the mirror. The reflective light valve can reflect its corresponding optical path to the light absorber.

[0056] Embodiment 5

[0057] On the basis of Embodiment 4, the following further improvements are made: A beam combiner is provided between the reflective light valve and the mirror. The optical path of the beam combiner coincides with the optical path of its corresponding low-power laser to indicate the position of its corresponding low-power laser on the standard power meter and the power meter to be calibrated; The beam combiner is set to load a low-power visible laser (indicating laser) for indication. The optical path of the visible laser completely coincides with the optical path of its corresponding infrared laser (low-power laser), that is, the low-power visible laser has the same pointing and the same position on the power meter as its corresponding low-power laser. When replacing the power meter, the position of the power meter can be determined first by using the low-power visible laser, which makes it easy to find the accurate position when replacing the power meter, improves the safety of operation, and prevents the infrared laser from hurting the operator. Figure 1 The solid line in the figure is the optical path of the low-power laser, and the dotted line is the optical path of the visible laser. The dotted line and the solid line should coincide. Figure 1 The dotted line and the solid line are separated to more intuitively show the two different optical paths.

[0058] Embodiment 6

[0059] On the basis of Embodiment 5, the following further improvements are made: After the beam superposition, the angle between the peripheral laser beam and the central laser beam is less than 1.5°, and the central laser beam is perpendicular to the surfaces of both the standard power meter and the power meter to be calibrated. The spot produced by all the low-power lasers after beam superposition on the surfaces of the standard power meter and the power meter to be calibrated coincides with the spot when there is only the central laser beam with a coincidence degree greater than 99%.

[0060] The method for calibrating a high-power laser power meter using the above device is as follows: While three low-power lasers with the same power are respectively passed through a beam expander, a polarizer, a laser sampler and a mirror in sequence, and then beam combined and superposed on the standard power meter and the power meter to be calibrated respectively to realize the calibration of the power meter to be calibrated; One of the low-power lasers is the central laser beam, and the rest are peripheral laser beams. The angle between the peripheral laser beams and the central laser beam after beam combination and superposition is less than 1.5°. The specific steps are as follows:

[0061] 1) After each low-power laser beam passes through a beam expander and a polarizer in sequence, it is sampled by a laser sampler, and the power of the sampled sample is measured by a laser sampling power meter. The power readings of each low-power laser at time t are I1(t), I2(t), I3(t), …… respectively. The total power of each low-power laser at time t, Is(t), is also a function of time, and Is(t) = I1(t) + I2(t) + I3(t) + ……;

[0062] 2) Combine and superimpose all the low-power lasers on a standard power meter. The reading of the standard power meter at time t is Ia(t); each laser sampling power meter and the standard power meter need to collect readings simultaneously. Through the readings at different times, a one-to-one corresponding functional relationship between Ia(t) and Is(t) is established;

[0063] 3) Combine and superimpose all the low-power lasers on the power meter to be calibrated. At the same time, collect the total reading Is(t) of each laser sampling power meter at time t and the reading Ia’(t) on the power meter to be calibrated. Taking Is(t) as a bridge, through the one-to-one corresponding functional relationship between Ia(t) and Is(t) obtained in step 2), the Ia(t) corresponding to Ia’(t) can be obtained, thus realizing the calibration; in the power range of 0W to 1000W, measurements are made every 5W to obtain a calibration curve of 0W to 1000W;

[0064] The sum of the readings Is(t) on the above sampling power meter and the reading Ia(t) on the standard power meter are sampled simultaneously, eliminating the interference of power fluctuations over time, and obtaining the functional relationship (one-to-one correspondence) between Is(t) and Ia(t); then replace it with the power meter to be measured and make the same measurement to obtain Is(t) and the reading Ia(t)’ of the power meter to be measured; taking Is(t) as a bridge, the reading of Ia(t)’ corresponds to the reading Ia(t) of the standard power meter, that is, the calibration of the power meter to be measured is realized.

[0065] When replacing the standard power meter and the power meter to be calibrated during the operation, it is not necessary to turn off the low-power laser. As long as the corresponding laser is reflected to the optical absorber by controlling the reflective optical valve, the time waste from laser startup to stabilization is avoided, and at the same time, the safety of the operation on the subsequent optical path is protected.

[0066] When replacing the power meter, the position of the power meter can be determined first by using a low-power visible laser, which is convenient for easily finding the accurate position when replacing the power meter, improving the safety of the operation and preventing the infrared laser from harming the operator.

Claims

1. A calibration method for a high-power laser power meter, characterized in that: At the same time, two or more low-power lasers with the same power are combined and superimposed on a standard power meter or a calibrated power meter to calibrate the calibrated power meter; among the low-power lasers, one is the central laser beam and the others are peripheral laser beams, and the angle between the peripheral laser beams and the central laser beam after combination and superposition is less than 5°; All low-power lasers pass through a beam expander and a polarizer in sequence, and then are combined and superimposed on a standard power meter or a calibrated power meter; A method for calibrating a high-power laser power meter includes the following steps connected in sequence: 1) After each low-power laser passes through a beam expander and a polarizer in sequence, sample it with a laser sampler and measure the power of the sampled sample with a laser sampling power meter. The power readings of each low-power laser at time t are I1(t), I2(t), I3(t)..., and the total power Is(t) of each low-power laser at time t is also a function of time, Is(t) = I1(t) + I2(t) + I3(t)+...; 2) Combine and superimpose all low-power lasers on a standard power meter. The reading of the standard power meter at time t is Ia(t); each laser sampling power meter and the standard power meter need to collect readings simultaneously. Through the readings at different times, a one-to-one correspondence function relationship between Ia(t) and Is(t) is established; 3) Combine and superimpose all low-power lasers on the calibrated power meter, and simultaneously collect the total reading Is(t) of each laser sampling power meter at time t and the reading Ia'(t) on the calibrated power meter. Taking Is(t) as a bridge, through the one-to-one correspondence function relationship between Ia(t) and Is(t) obtained in step 2), the Ia(t) corresponding to Ia'(t) can be obtained, thereby realizing calibration.

2. The high-power laser power meter calibration method according to claim 1, wherein: A reflective light valve and a light absorber are provided downstream of each laser sampler, and the reflective light valve can reflect its corresponding laser to the light absorber.

3. The high-power laser power meter calibration method according to claim 2, characterized in that: A beam combiner is provided between the reflective light valve and the mirror. The optical path of the beam combiner coincides with the optical path of its corresponding low-power laser to indicate the position of its corresponding low-power laser on the standard power meter and the calibrated power meter, so as to determine the positions of the standard power meter and the calibrated power meter.

4. The high-power laser power meter calibration method according to any one of claims 1-3, characterized in that: The angle between the peripheral laser beam and the central laser beam is less than 1.5°. The spot generated on the surfaces of the standard power meter and the calibrated power meter after all low-power lasers are combined and superimposed coincides with the spot when only the central laser beam is present by more than 95%; the central laser beam is perpendicular to the surfaces of both the standard power meter and the calibrated power meter.

5. A high-power laser power meter calibration device, characterized in that: It includes a standard power meter, a power meter to be calibrated, and a low-power laser optical path; There are two or more low-power laser optical paths. One of the low-power laser optical paths is the central laser optical path, and the others are peripheral laser optical paths. All low-power laser optical paths are combined and superimposed on the standard power meter or the power meter to be calibrated. After combination and superposition, the angle between the peripheral laser beam and the central laser beam is less than 5°; All low-power laser optical path structures are the same. Along the propagation direction of the optical path, each low-power laser optical path includes a laser, a beam expander, a polarizer, and a mirror connected in sequence; A laser sampler and a laser sampling power meter are provided on each low-power laser optical path. The laser sampler is arranged between the polarizer and the mirror, and the laser sampling power meter is used to measure the power of the sample collected by the laser sampler. The central laser beam is perpendicular to the surfaces of both the standard power meter and the power meter to be calibrated. The coincidence degree of the light spots generated on the surfaces of the standard power meter and the power meter to be calibrated after all the low-power laser beams are combined and superimposed is greater than 95% with the light spot when only the central laser beam exists.

6. The high-power laser power meter calibration device according to claim 5, characterized in that: A reflective light valve and a light absorber are provided between each laser sampler and the mirror. The reflective light valve can reflect its corresponding optical path to the light absorber.

7. The high-power laser power meter calibration device according to claim 6, characterized in that: A beam combiner is provided between the reflective light valve and the mirror. The optical path of the beam combiner coincides with the optical path of its corresponding low-power laser to indicate the position of its corresponding low-power laser on the standard power meter and the power meter to be calibrated, thereby determining the positions of the standard power meter and the power meter to be calibrated; after beam combination and superposition, the included angle between the peripheral laser beam and the central laser beam is less than 1.5°.

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