High power laser power measurement system

Abstract

The application discloses a high-power laser power measuring system and relates to the technical field of laser measurement. The application comprises a measuring mirror, a measuring module and a mirror group. The non-reflective surface of the measuring mirror is connected with the measuring end of the measuring module, and the measuring direction of the measuring module is perpendicular to the reflective surface of the measuring mirror. The mirror group is used for changing the optical path of the incident high-power laser, so that the high-power laser is emitted along the direction of the incident optical path after being reflected by the measuring mirror. The measuring system has the advantages of small volume, light weight, fast response speed, no need of water cooling, on-line measurement, high measurement accuracy and good stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser measurement technology, in particular to a high-power laser power measurement system. BACKGROUND

[0002] High-power laser, usually refers to the laser emitted by high-power laser, its output power is usually above 1 kilowatt, high-power laser has important application in the field of industrial processing, military defense and scientific research. In recent years, with the development of laser technology, the output power level of laser is constantly improved. The accurate measurement of power is the basis of high-power laser research and application, and the rapid and accurate measurement of high-power laser power has always been a difficult problem.

[0003] At present, the existing high-power laser measurement methods mainly have two types: calorimetric method and sampling method.

[0004] Calorimetric method absorbs all high-power laser by absorbing material and converts it into heat, and the temperature rise of the heat sink or water in the measuring device is used to obtain the laser power. However, the calorimetric method uses a device with large volume, heavy weight and slow response speed, and needs to be equipped with a water cooler or a water tank, and the higher the measured power, the larger the volume of the device, and the surface of the absorbing material of the measuring device is easily damaged by laser.

[0005] The sampling method takes a small part of the high-power laser out for measurement by a sampling device, and then calculates the power of the laser through the sampling ratio of the device. The sampling method measuring device has small volume, but the sampling device temperature rises and produces nonlinear benefits under high-power laser irradiation, and the sampling ratio is easy to change, resulting in measurement deviation. Compared with the calorimetric method, the measurement error is large and the stability is poor. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a high-power laser power measurement system to solve the problems of the prior art.

[0007] The technical solution of the present application to solve the above technical problems is as follows:

[0008] A high-power laser power measurement system, comprising: a measurement mirror, a measurement module and a mirror group, wherein the non-reflective surface of the measurement mirror is connected with the measurement end of the measurement module, and the measurement direction of the measurement module is perpendicular to the reflective surface of the measurement mirror, and the mirror group is used to change the optical path of the incident high-power laser, so that the high-power laser is emitted along the direction of the incident light path after being reflected by the measurement mirror.

[0009] Another technical solution of the present application to solve the above technical problems is as follows:

[0010] The application discloses a high-power laser power measuring system, which comprises a measuring mirror, a measuring module and a mirror.

[0011] Another technical solution of the application for solving the above technical problem is as follows:

[0012] The application discloses a high-power laser power measuring system, which comprises a measuring mirror, a measuring module and a mirror.

[0013] The non-reflective surface of the first measuring mirror is connected with the measuring end of the measuring module, and the measuring direction of the measuring module is at a preset angle with the reflective surface of the first measuring mirror.

[0014] The first mirror is used for changing the direction of the outgoing light path of the high-power laser reflected by the first measuring mirror, so that the high-power laser is shot to the second mirror.

[0015] Since photons have momentum although they have no static mass, pressure is generated when laser is irradiated to the surface of an object, and thus the high-power laser power measuring system is used for collecting the light pressure generated by the high-power laser on the measuring mirror by the measuring module, and the power of the high-power laser can be measured according to the proportional relationship between the measuring module and the laser power.

[0016] The advantages of the additional aspects of the application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A schematic diagram of a structure provided for an embodiment of the high-power laser power measurement system of the present invention;

[0018] Figure 2 Another structural schematic diagram of an embodiment of the high-power laser power measurement system of the present invention;

[0019] Figure 3 This is yet another structural schematic diagram of an embodiment of the high-power laser power measurement system of the present invention. Detailed Implementation

[0020] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments described are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0021] like Figure 1 The diagram shown is a structural schematic of an embodiment of the high-power laser power measurement system of the present invention. The high-power laser power measurement system includes: a measuring mirror 10, a measuring module 20, and a mirror group 30. The non-reflective surface of the measuring mirror 10 is connected to the measuring end of the measuring module 20, and the measuring direction of the measuring module 20 is perpendicular to the reflective surface of the measuring mirror 10. The mirror group 30 is used to change the optical path of the incident high-power laser, so that the high-power laser is reflected by the measuring mirror 10 and emitted along the direction of the incident optical path.

[0022] It should be noted that, in order to reduce losses and heat generation, the reflectivity of the reflector 10 and the reflector group 30 is measured to be higher than 99.9%, and the window transmittance is higher than 99.8%.

[0023] Preferably, the reflector is measured and its reflectivity is 99.99%.

[0024] The measurement module 20 can be a force sensor, a mass sensor, or a displacement sensor.

[0025] Taking a mass sensor as an example, when a laser with power P shines on the measuring mirror 10, the mass m measured by the measuring module 20 is:

[0026]

[0027] Where c is the speed of light in vacuum, g is the acceleration due to gravity, θ is the laser incident angle, and R and A are the reflectivity and absorptivity of the mirror, respectively. When the laser shines on the measuring mirror, it will generate light pressure on the reflective surface of the measuring mirror. The power of the incident laser can be obtained from the mass reading of the measuring module 20. It should be understood that the relationship between the mass reading of the measuring module 20 and the laser power can be determined in advance.

[0028] For example, with Figure 1 For example, supposeFigure 1 When the incidence angle of the laser to the first mirror is 55°, the incidence angle of the laser to the measuring mirror 10 is 20°, and the incidence angle of the laser to the second mirror is 55°, the equivalent laser power resolution is about 1.56 W when the resolution of the measuring module 20 is 1 μg, that is, the conversion coefficient of mass and laser power is 1.56 W / μg. The upper limit of the power measurement of the measuring system is only limited by the damage threshold of the measuring mirror 10, and thus the upper limit of the power measurement can reach 100 kW or even higher, while the measuring system has the advantages of fast response speed, high measurement accuracy, and on-line measurement.

[0029] Optionally, the model of the mass sensor can be XSE105.

[0030] It should be noted that, Figure 1 The structure diagram given is only an example, and two mirrors are used in the diagram. Due to technical limitations, the laser is usually incident in the horizontal direction, and thus the direction of the light path needs to be changed so that the laser is incident on the measuring mirror 10, and then the laser is made to exit along the original light path through the second mirror. The placement angle of the two mirrors can be set according to actual needs. For example, the incidence angle of the laser to the first mirror is preferably 55°, and can alternatively be between 50° and 60°. The incidence angle of the laser to the measuring mirror 10 is preferably 20°, and can alternatively be between 15° and 30°. The incidence angle of the laser to the second mirror is preferably 55°, and can alternatively be between 50° and 60°.

[0031] It should be understood that, based on the above, Figure 1 more mirrors can be arranged to make the laser reflect multiple times and then be incident on the measuring mirror 10, and then a symmetrical structure can be arranged on the reflected light path of the measuring mirror 10 to make the light path exit along the original light path. This can be arranged by those skilled in the art according to the reflection principle of the mirror, and all can realize the function of making the light path exit along the original light path, which will not be described here.

[0032] Optionally, as Figure 1 shown, a housing 40 can also be arranged to arrange the entire system in the housing 40, and a window can be arranged at the position through which the light path passes.

[0033] Since photons have momentum although they have no static mass, pressure will be generated when laser irradiates on the surface of the object, and the high-power laser power measuring system provided by the application can collect the light pressure generated by the high-power laser on the measuring mirror 10 through the measuring module 20, and the power of the high-power laser can be measured according to the proportional relationship between the measuring module 20 and the laser power. Compared with the calorimetric method, the measuring system has the advantages of small volume, light weight, fast response speed, no need for water cooling and on-line measurement. Since the measuring direction of the measuring module 20 is perpendicular to the reflecting surface of the measuring mirror 10, compared with the sampling method, the measuring system has the advantages of high measuring accuracy, good stability, fast response speed, high measuring accuracy and on-line measurement.

[0034] Optionally, in some possible embodiments, the measuring direction of the measuring module 20 is perpendicular to the direction of the incident light path of the high-power laser, and the measuring direction of the measuring module 20 is the direction of gravity.

[0035] By setting the measuring direction of the measuring module 20 as the direction of gravity, the torque generated by the self-weight of the measuring mirror can be avoided to affect the measuring result of the measuring module 20, and the additional measuring error introduced by the inconsistency between the calibration posture and the measuring posture of the measuring module 20 is eliminated. The self-weight of the measuring mirror 10 can be less than the maximum weight of the measuring module 20, and the torque generated by the self-weight of the measuring mirror 10 will not affect the measuring result, thereby improving the accuracy of the measuring result.

[0036] Optionally, in some possible embodiments, as shown in Figure 1 The mirror group 30 includes a first mirror 31 and a second mirror 32. The first mirror 31 is arranged in the incident light path of the high-power laser, and is used to change the direction of the incident light path of the high-power laser, so that the high-power laser is reflected to the measuring mirror 10 at a preset angle. The second mirror 32 is arranged in the outgoing light path of the high-power laser, and is used to change the direction of the outgoing light path of the high-power laser reflected by the measuring mirror 10, so that the high-power laser is emitted along the direction of the incident light path.

[0037] It should be understood that the preset angle can be set according to actual needs, which has been described in the foregoing embodiments and will not be repeated here.

[0038] By using two mirrors, the loss of the laser caused by reflection during propagation can be reduced to the greatest extent, so that the measuring result is more accurate.

[0039] It should be understood that, in some embodiments, all or part of the above optional embodiments can be included.

[0040] As shown in Figure 2As shown, another structural schematic diagram provided by an embodiment of the high-power laser power measuring system is shown, the high-power laser power measuring system comprises a measuring mirror 10, a measuring module 20 and a mirror 33, and the laser is a laser source, wherein the non-reflective surface of the measuring mirror 10 is connected with the measuring end of the measuring module 20, the measuring direction of the measuring module 20 is at a preset angle with the reflective surface of the measuring mirror 10, and the mirror 33 is used for changing the light path of the high-power laser reflected by the measuring mirror 10, so that the high-power laser is emitted along the direction of the incident light path.

[0041] It should be understood that the preset angle can be set according to actual needs, for example, Figure 2 The angle in the formula is 45 degrees, and the mirror 33 is arranged in parallel with the measuring mirror 10, so that the laser can be emitted along the original light path direction, and the influence on the laser propagation is reduced.

[0042] It should be noted that in order to reduce the loss and heat, the reflectivity of the measuring mirror 10 and the mirror 33 is higher than 99.9%, and the transmittance of the window is higher than 99.8%.

[0043] Preferably, the reflectivity of the measuring mirror and the mirror is 99.99%.

[0044] The measuring module 20 can be a force sensor, a mass sensor or a displacement sensor.

[0045] Taking the mass sensor as an example, when the laser with a power of P is irradiated on the measuring mirror 10, the mass m measured by the measuring module 20 is:

[0046]

[0047] Wherein, c is the speed of light in vacuum, g is the acceleration of gravity, θ is the laser incidence angle, and R and A are the reflectivity and absorption of the mirror respectively. When the laser is irradiated on the measuring mirror, the optical pressure will be generated on the reflective surface of the measuring mirror, and the power of the incident laser can be obtained according to the mass reading of the measuring module 20. It should be understood that the relationship between the mass reading of the measuring module 20 and the laser power can be determined in advance.

[0048] The conversion coefficient of the mass of the measuring module and the laser power is affected by the placement angle of the mirror, which can be measured by a limited number of experiments by those skilled in the art, and will not be described here. The upper limit of the power measurement of the measuring system is only limited by the damage threshold of the measuring mirror 10, so the upper limit of the power measurement can reach 100kW or even higher, and the measuring system also has the advantages of fast response speed, high measurement accuracy, online measurement and the like.

[0049] Optionally, the model of the mass sensor can be XSE105.

[0050] It should be understood that the measuring module 20 can also be arranged on the side of the measuring mirror 10. Figure 2Based on this, more reflectors are set up to make the laser reflect multiple times and then shoot towards the measuring reflector 10. Then, a symmetrical structure is set up on the reflected light path of the measuring reflector 10 so that the light path is emitted along the original light path. This is something that those skilled in the art can set up themselves based on the reflection principle of the reflector, and all of them can achieve the function of making the light path be emitted along the original light path. It will not be described in detail here.

[0051] Alternatively, an enclosure can be installed to house the entire system, with windows positioned where the light path passes.

[0052] Since photons have momentum but no rest mass, they generate pressure when a laser irradiates the surface of an object. Therefore, the high-power laser power measurement system provided by this invention collects the light pressure generated by the high-power laser on the measuring mirror 10 through the measurement module 20. Based on the proportional relationship between the measurement module 20 and the laser power, the power of the high-power laser can be measured. Compared with the calorimetric method, the measurement system is small in size, light in weight, fast in response speed, does not require water cooling, and can be measured online. Compared with the sampling method, it has high measurement accuracy and good stability, and also has the advantages of fast response speed, high measurement accuracy, and online measurement capability.

[0053] Optionally, in some possible implementations, the measurement direction of the measurement module 20 is perpendicular to the direction of the incident optical path of the high-power laser, and the measurement direction of the measurement module 20 is the direction of gravity.

[0054] By setting the measurement direction of the measurement module 20 to the direction of gravity, the torque generated by the self-weight of the reflector can be avoided from affecting the measurement results of the measurement module 20. This eliminates the additional measurement error introduced by the inconsistency between the calibration attitude and the measurement attitude of the measurement module 20. As long as the self-weight of the reflector 10 does not exceed the maximum weighing capacity of the measurement module 20, no torque will be generated that will affect the measurement results, thereby improving the accuracy of the measurement.

[0055] It is understood that some implementations may include all or part of the above optional implementations.

[0056] like Figure 3 The diagram shown illustrates another structural embodiment of the high-power laser power measurement system of the present invention. This high-power laser power measurement system includes: a measurement mirror group, a measurement module 20, and a mirror group. The measurement mirror group includes: a first measurement mirror 11 and a second measurement mirror 12. The mirror group also includes: a first mirror 31 and a second mirror 32. The laser is a laser source.

[0057] The non-reflective surface of the first measurement mirror 11 is connected with the measurement end of the measurement module 20, and the measurement direction of the measurement module 20 is at a preset angle with the reflective surface of the first measurement mirror 11; the non-reflective surface of the second measurement mirror 12 is connected with the measurement end of the measurement module 20, and the measurement direction of the measurement module 20 is at a preset angle with the reflective surface of the second measurement mirror 12.

[0058] The first mirror 31 is used to change the direction of the outgoing light path of the high-power laser reflected by the first measurement mirror 11, so that the high-power laser is shot to the second mirror 32; the second mirror 32 is used to change the direction of the outgoing light path of the high-power laser reflected by the first mirror 31, so that the high-power laser is shot to the second measurement mirror 12; the second measurement mirror 12 is used to change the direction of the outgoing light path of the high-power laser reflected by the second mirror 32, so that the high-power laser is shot along the direction of the incident light path of the first measurement mirror 11.

[0059] It should be understood that the preset angle can be set according to actual needs, for example, Figure 3 The angle in the above formula is 45 degrees, and the mirror is arranged to be parallel to the corresponding measurement mirror, so that the laser can be shot along the original light path direction, reducing the influence on the laser propagation.

[0060] It should be noted that, in order to reduce the loss and heat, the reflectivity of the measurement mirror and the mirror is higher than 99.9%, and the transmittance of the window is higher than 99.8%.

[0061] Preferably, the reflectivity of the measurement mirror and the mirror is 99.99%.

[0062] The measurement module 20 can be a force sensor, a mass sensor or a displacement sensor.

[0063] Taking the mass sensor as an example, when the laser with a power of P is irradiated on the measurement mirror, the mass m measured by the measurement module 20 is:

[0064]

[0065] Wherein, c is the speed of light in vacuum, g is the acceleration of gravity, θ is the laser incidence angle, and R and A are the reflectivity and absorption of the mirror, respectively. When the laser is irradiated on the measurement mirror, the light pressure will be generated on the reflective surface of the measurement mirror. According to the mass reading of the measurement module 20, the power of the incident laser can be obtained. It should be understood that the relationship between the mass reading of the measurement module 20 and the laser power can be determined in advance.

[0066] The conversion coefficient of the measurement module mass and the laser power is affected by the placement angle of the mirror, which can be measured by the skilled person in the art through a limited number of experiments, and will not be described here. The upper limit of the power measurement of the measurement system is only limited by the damage threshold of the measurement mirror, so the upper limit of the power measurement can reach 100 kW or even higher, while also having the advantages of fast response speed, high measurement accuracy, and online measurement.

[0067] It should be understood that since the measurement module is connected with two measurement mirrors, the actual power is half of the measured power.

[0068] Optionally, the model of the mass sensor can be XSE105.

[0069] It should be understood that more mirrors can also be arranged on the basis of Figure 3 to make the laser reflect multiple times and then shoot at the measurement mirror, and then symmetrically arranged structures are arranged on the reflected light path of the measurement mirror to make the light path shoot in the original light path direction. The skilled person can arrange them according to the reflection principle of the mirror, and all of them can realize the function of making the light path shoot in the original light path direction, which will not be described here.

[0070] Optionally, a housing can also be provided to arrange the entire system in the housing, and a window is provided at the position where the light path passes through.

[0071] Since photons have momentum although they have no rest mass, when the laser irradiates the surface of the object, pressure will be generated. Therefore, the high-power laser power measurement system provided by the application can collect the optical pressure generated by the high-power laser on the measurement mirror through the measurement module 20, and according to the proportional relationship between the measurement module 20 and the laser power, the power of the high-power laser can be measured. Compared with the calorimetric method, the measurement system has the advantages of small volume, light weight, fast response speed, no need for water cooling, and online measurement. Compared with the sampling method, the measurement accuracy is high and the stability is good, and it also has the advantages of fast response speed, high measurement accuracy, and online measurement.

[0072] Optionally, in some possible embodiments, the measurement direction of the measurement module 20 is perpendicular to the direction of the incident light path of the high-power laser, and the measurement direction of the measurement module 20 is the direction of gravity.

[0073] By setting the measurement direction of the measurement module 20 as the direction of gravity, the torque generated by the self-weight of the measurement mirror can be avoided to affect the measurement result of the measurement module 20, and the additional measurement error introduced by the inconsistency between the calibration attitude and the measurement attitude of the measurement module 20 is eliminated. The self-weight of the measurement mirror should not exceed the maximum weighing of the measurement module 20, and will not produce torque to affect the measurement result, thereby improving the accuracy of the measurement.

[0074] It is understood that in some embodiments, all or part of the above optional embodiments can be included.

[0075] It is to be understood that the description of the description of the present specification, the reference to the term "one embodiment", "some embodiments", "example", "specific example" or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the skilled person can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, without contradiction.

[0076] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A high power laser power measurement system, characterized by, The application relates to a high-power laser power measuring system. The measuring mirror group comprises a first measuring mirror and a second measuring mirror. The mirror group comprises a first mirror and a second mirror, and the laser is a laser source. The non-reflective surface of the first measuring mirror is connected with the measuring end of the measuring module, and the measuring direction of the measuring module is at a preset angle with the reflective surface of the first measuring mirror; the non-reflective surface of the second measuring mirror is connected with the measuring end of the measuring module, and the measuring direction of the measuring module is at a preset angle with the reflective surface of the second measuring mirror. The first mirror is used for changing the direction of the outgoing light path of the high-power laser reflected by the first measuring mirror, so that the high-power laser is shot towards the second mirror; the second mirror is used for changing the direction of the outgoing light path of the high-power laser reflected by the first mirror, so that the high-power laser is shot towards the second measuring mirror; and the second measuring mirror is used for changing the direction of the outgoing light path of the high-power laser reflected by the second mirror, so that the high-power laser is shot along the direction of the incident light path of the first measuring mirror. In order to reduce the loss and heat, the reflectivity of the measuring mirror and the mirror is higher than 99.9%, and the transmittance of the window is higher than 99.8%. The measuring module is a force sensor, a mass sensor or a displacement sensor. If the mass sensor is used, when the laser with the power P is irradiated on the measuring mirror, the mass m measured by the measuring module is: Wherein, c is the speed of light in vacuum, g is the acceleration of gravity, theta is the laser incidence angle, R and A are the reflectivity and absorption of the mirror respectively; when the laser is irradiated on the measuring mirror, the light pressure is generated on the reflective surface of the measuring mirror, and the power of the incident laser is obtained according to the mass reading of the measuring module; The application further comprises a shell, which is used for arranging the whole system in the shell, and the window is arranged at the position through which the light path passes. Since the photons have no static mass but have momentum, when the laser is irradiated on the surface of the object, the pressure is generated, so that the light pressure generated by the high-power laser on the measuring mirror is collected through the measuring module, the power of the high-power laser is measured according to the proportional relationship between the measuring module and the laser power, compared with the calorimetric method, the measuring system is small in size, light in weight, fast in response speed, does not need water cooling and can be measured on line, compared with the sampling method, the measuring accuracy is high and the stability is good, and the measuring system has the advantages of fast response speed, high measuring accuracy and on-line measurement. The measuring direction of the measuring module is perpendicular to the direction of the incident light path of the high-power laser, and the measuring direction of the measuring module is the direction of gravity. By arranging the measuring direction of the measuring module as the direction of gravity, the torque generated by the self weight of the measuring mirror is avoided to influence the measuring result of the measuring module, the additional measuring error introduced by the inconsistency between the calibration posture and the measuring posture of the measuring module is eliminated, the self weight of the measuring mirror does not exceed the maximum weighing of the measuring module, the torque does not influence the measuring result, and therefore the measuring accuracy is improved. ​

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