Laser photoelectric and photo-thermal composite measuring device

Abstract

The invention relates to a laser photoelectric and photo-thermal composite measurement device, belongs to the technical field of laser parameter measurement devices, and solves the technical problem that energy measurement is difficult to perform due to fixed attenuation multiplying power and non-uniform temperature distribution in attenuation sampling. The device comprises an optical incident window, an energy absorption cavity, a uniform scattering material, a temperature probe group, a pressure probe group, an optical emergent window and a photoelectric detector array. A closed space formed by the optical incidence window, the energy absorption cavity and the optical emergence window is filled with the uniform scattering material, and laser sequentially penetrates through the optical incidence window, the uniform scattering material and the optical emergence window to reach the photoelectric detector array. And the temperature probe group and the pressure probe group are used for respectively measuring the temperature and the pressure in the energy absorption cavity. The method is used for measuring laser performance parameters.

Description

Technical Field

[0001] The invention belongs to the technical field of laser parameter measurement, and in particular relates to a laser photoelectric and photothermal composite measurement device. Background Art

[0002] In the measurement of high-energy laser parameters, the photodetector array sampling method is often used to obtain the spatiotemporal distribution information of the power density of the strong laser spot. Since the laser power density at the test position is generally high, in actual testing, the measured laser power density needs to be reasonably attenuated to meet the range of the photodetector.

[0003] At present, the attenuation units used all use solid materials as scattering materials. The Chinese invention patent with the publication number CN104019891A discloses an attenuation sampling device for high-energy laser incident at a large angle. The device includes a front panel, an attenuation unit and a rear panel. The front panel is provided with a sampling straight hole for laser incidence, and the rear panel is provided with a laser exit hole. The attenuation unit includes a front transmission window, a rear transmission window and a cylindrical cavity. The cylindrical cavity is coaxially arranged with the sampling straight hole and the laser exit hole, and the cylindrical cavity is filled with granular optical body scattering materials. The laser is coupled into the attenuation unit through the sampling hole, and is emitted from the laser exit hole after being absorbed by the inner wall and the material and body scattered. The beam energy can be redistributed in a large range of space, and has a homogenization effect. At the same time, large-angle attenuation sampling is realized when the laser is obliquely incident, and the laser power density can be greatly attenuated, and it can be used for light intensity detection with high spatial resolution. However, when parameters such as the power density of the incident laser change, the attenuation factor of the attenuation sampling device is relatively fixed. In order to adjust the attenuation factor, the mechanical structure of the attenuation device needs to be redesigned, manufactured and processed, which is difficult to achieve. Secondly, the solid body scattering material in the attenuation sampling device has uneven temperature distribution due to insufficient contact, and it is difficult to use it as an energy measurement unit by measuring the overall temperature of the body scattering material, and it is difficult to achieve photoelectric and photothermal composite measurement. Summary of the invention

[0004] In order to overcome the shortcomings of the attenuation sampling device, such as fixed attenuation ratio and uneven temperature distribution, the present invention proposes a laser photoelectric and photothermal composite measuring device.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] A laser photoelectric and photothermal composite measuring device comprises an optical incident window, an energy absorption cavity, a uniform scattering material, a temperature probe group, a pressure probe group, an optical exit window, and a photoelectric detector array.

[0007] The energy absorption cavity is in the shape of a circular tube, the optical incident window and the optical exit window are in the shape of a disc, the optical incident window and the optical exit window are tightly connected to the end of the energy absorption cavity, the optical incident window, the energy absorption cavity and the optical exit window form a closed space, and the uniform scattering material fills the closed space.

[0008] The laser passes through the optical incident window, uniform scattering material, optical exit window, and photodetector array in sequence. The photodetector array is used to measure the spatiotemporal distribution of the attenuated laser power density.

[0009] The temperature probe group and the pressure probe group are arranged in the energy absorption cavity, adjacent to the optical exit window, and are used to measure the temperature and pressure in the energy absorption cavity respectively.

[0010] In the above-mentioned laser, photoelectric and photothermal composite measuring device, the uniform scattering material is an aerosol or a liquid scattering material.

[0011] In the above-mentioned laser, photoelectric and photothermal composite measuring device, the liquid scattering material is a metal nanoparticle solution or a carbon nanoparticle solution.

[0012] In the above-mentioned laser, photoelectric and optical thermal composite measuring device, the optical incident window is quartz glass coated with a reflective medium film.

[0013] In the above-mentioned laser photoelectric and photothermal composite measuring device, the optical output window is made of quartz glass.

[0014] In the above laser photoelectric photothermal composite measuring device, the temperature probe group includes a plurality of temperature probes, and the plurality of temperature probes are evenly distributed axially in the energy absorption cavity. The pressure probe group includes a plurality of pressure probes, and the plurality of pressure probes are evenly distributed axially in the energy absorption cavity. The pressure probe group is located outside the temperature probe group.

[0015] In the above-mentioned laser photoelectric and photothermal composite measuring device, the temperature probe group includes 4 temperature probes, and the 4 temperature probes are located on the same circumference of the cross section of the energy absorption cavity; the pressure probe group includes 4 pressure probes, and the 4 pressure probes are located on the same circumference of the cross section of the energy absorption cavity.

[0016] The beneficial effects of the present invention are:

[0017] A laser photoelectric and photothermal composite measurement device. The laser is coupled into the energy absorption cavity through the incident optical window, and is scattered and absorbed by the uniform scattering material in the energy absorption cavity before being emitted from the laser exit window. Due to the uniform scattering material in the cavity, the temperature distribution is uniform, and the laser becomes a uniform beam after passing through the energy absorption cavity.

[0018] A laser photoelectric and photothermal composite measuring device realizes the adjustment of attenuation magnification by changing the type of uniform material in an energy absorption cavity or changing the concentration, and the attenuation magnification adjustment is easy to achieve.

[0019] A laser photoelectric and photothermal composite measurement device. After absorbing the incident laser energy, the temperature and pressure of the uniform scattering material in the energy absorption cavity rise. The temperature probe group and pressure probe group in the cavity measure the temperature and pressure changes. Compared with the method of measuring energy only by temperature, a calibration method is added, and the measurement results of the photoelectric detector array are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view of a photoelectric and photothermal composite measuring device according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the distribution of a temperature probe group and a pressure probe group in accordance with an embodiment of the present invention;

[0022] Figure 3 FIG. 1 is a schematic diagram of the incident light scattering principle according to an embodiment of the present invention.

[0023] Figure numerals: 1. optical incident window, 2. energy absorption cavity, 3. uniform scattering material, 4. temperature probe group, 5. pressure probe group, 6. optical exit window, 7. photodetector array. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Embodiment 1

[0026] A laser photoelectric and photothermal composite measurement device based on uniform scattering materials, such as Figure 1 As shown, it includes an optical incident window 1, an energy absorption cavity 2, a uniform scattering material 3, a temperature probe group 4, a pressure probe group 5, an optical exit window 6, a photodetector array 7, etc., which are arranged in sequence along the laser incident direction; wherein the optical incident window 1 is made of quartz glass coated with a reflective medium film, and the energy absorption cavity 2 is filled with a uniform scattering material 3, which is mainly a uniform aerosol or a uniform liquid scattering material, and the liquid scattering material can contain a metal nanoparticle solution, a carbon nanoparticle solution, etc. Its temperature and pressure are measured respectively by using a temperature probe group 4 and a pressure probe group 5 uniformly distributed along the axial direction, and the optical exit window 6 is made of a window material such as quartz with low optical absorption, and a photodetector array 7 is arranged behind the exit window to measure the spatiotemporal distribution of the attenuated high-energy laser power density.

[0027] In the laser photoelectric photothermal composite measurement device of the present invention, the energy Q of the energy absorption cavity can be measured by Q=cmΔT, where c is the specific heat capacity of the uniform scattering material 3, m is the mass of the uniform scattering material 3, and ΔT is the temperature rise of the uniform scattering material 3. The temperature can be directly measured by the temperature probe group, and the accuracy of the measurement can be increased after the temperature of multiple points is averaged.

[0028] According to the relationship between mass m, volume V, pressure p and temperature T represented by the equation of state:

[0029] For example, the equation of state of a gas is pV=nRT, where p is pressure, V is volume, n is the amount of substance, T is temperature, and R is the molar gas constant. It can be seen that T=pV / nR;

[0030] It can be seen that the measured pressure value p can be inferred from the temperature value T, and then the energy Q can be obtained. Therefore, adding a pressure probe adds a measurement method, which can ensure the accuracy of energy measurement when the temperature probe fails.

[0031] like Figure 3 As shown, the incident laser travels along Figure 3 After coupling into the cavity in the direction of the middle arrow, due to the scattering characteristics of the uniform body scattering material, the distribution of the scattered light intensity I(θ) in space conforms to Lambert's cosine law, that is, I(θ)=I0cos(θ), where I0 is the incident light intensity, θ is the angle with the incident direction, and I(θ) is the light intensity in the direction of the angle θ. The beam energy can be redistributed in a larger range of space through scattering, and has a homogenizing effect. Regardless of the incident angle, it will undergo multiple reflections, which can ensure good angle characteristics. Therefore, a photodetector array can be used for measurement after the exit window. The energy absorption cavity simultaneously realizes quantitative attenuation sampling and homogenization of the photoelectric power density.

Claims

1. A laser photoelectric photothermal composite measurement device, characterized in that: It comprises an optical incident window (1), an energy absorption cavity (2), a uniform scattering material (3), a temperature probe group (4), a pressure probe group (5), an optical exit window (6), and a photoelectric detector array (7); The energy absorption cavity (2) is in the shape of a circular tube, the optical incident window (1) and the optical exit window (6) are in the shape of a disc, the optical incident window (1) and the optical exit window (6) are tightly connected to the ends of the energy absorption cavity (2); the optical incident window (1), the energy absorption cavity (2) and the optical exit window (6) form a closed space, and the uniform scattering material (3) fills the closed space; The laser light sequentially passes through the optical incident window (1), the uniform scattering material (3), the optical exit window (6), and reaches the photodetector array (7); the photodetector array (7) is used to measure the spatiotemporal distribution of the laser power density after attenuation; The temperature probe group (4) and the pressure probe group (5) are arranged in the energy absorption chamber (2) and are adjacent to the optical exit window (6); the temperature probe group (4) and the pressure probe group (5) are used to measure the temperature and pressure in the energy absorption chamber (2), respectively.

2. The laser, photoelectric, and photothermal composite measurement device according to claim 1, characterized in that: The uniform scattering material (3) is an aerosol or a liquid scattering material.

3. The laser, photoelectric, and photothermal composite measurement device according to claim 2, characterized in that: The liquid scattering material is a metal nanoparticle solution or a carbon nanoparticle solution.

4. The laser, photoelectric, and photothermal composite measurement device according to claim 1, characterized in that: The optical incident window (1) is quartz glass coated with a reflective medium film.

5. The laser, photoelectric, and photothermal composite measurement device according to claim 1, characterized in that: The optical exit window (6) is made of quartz glass.

6. The laser, photoelectric, and photothermal composite measurement device according to claim 1, characterized in that: The temperature probe group (4) includes a plurality of temperature probes, which are evenly distributed axially in the energy absorption chamber (2); the pressure probe group (5) includes a plurality of pressure probes, which are evenly distributed axially in the energy absorption chamber (2); and the pressure probe group (5) is located outside the temperature probe group (4).

7. The laser, photoelectric, and photothermal composite measurement device according to claim 1, characterized in that: The temperature probe group (4) includes four temperature probes, which are located on the same circumference of the cross section of the energy absorption chamber (2); the pressure probe group (5) includes four pressure probes, which are located on the same circumference of the cross section of the energy absorption chamber (2).

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