Photoelectric photo-thermal composite attenuation detection unit and detection array based on solid scattering material

Abstract

The invention relates to a photoelectric and photo-thermal composite attenuation detection unit and a detection array based on a solid scattering material, belongs to the technical field of photoelectric measurement, and solves the technical problems that the photoelectric attenuation multiple of the detection unit is adjustable and calibration is not needed during photoelectric and photo-thermal composite attenuation detection. The detection unit comprises an energy absorber, a scattering sheet, a thermistor and a stud. The energy absorber is sequentially provided with a conical hole, a sampling hole and a cavity from top to bottom, a plurality of stacked scattering sheets are located in the cavity, the stud is installed in an internal thread of the cavity, the stud is provided with an emitting hole, and laser sequentially passes through the conical hole, the sampling hole and the scattering sheets and is emitted out of the emitting hole. The detection array comprises a plurality of detection units, a supporting plate and a protection plate. The protection plate is provided with a protection plate incident hole, the supporting plate is provided with a supporting plate emergent hole, and laser sequentially passes through the protection plate incident hole and the detection unit and is emitted out of the supporting plate emergent hole. The device is used for photoelectric and photo-thermal composite attenuation detection.

Description

Technical Field

[0001] The present invention belongs to the technical field of photoelectric measurement equipment, and in particular relates to a photoelectric and photothermal composite attenuation detection unit and a detection array based on solid scattering materials. 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 can generally only meet the needs of photoelectric measurement. The Chinese invention patent with publication number CN102384783A discloses a high-energy laser semi-integrating sphere array attenuator, including a front panel, a rear panel and a plurality of attenuation units arranged along the laser incident direction. The attenuation unit includes a large-angle sampling cone hole arranged on the front panel, a hemispherical cavity arranged on the rear panel, and a laser exit hole arranged at the edge of the hemispherical cavity and perpendicular to the rear panel. The positions of the large-angle sampling cone hole and the hemispherical cavity correspond one to one, and the large-angle sampling cone hole and the laser exit hole are respectively located on both sides of the semi-integrating sphere cavity. The laser is coupled into the hemispherical cavity through the large-angle sampling cone hole, and is emitted from the laser exit hole after absorption and diffuse reflection by the semi-integrating sphere cavity, thereby achieving a significant attenuation of the laser power density and meeting the attenuation sampling when the laser is obliquely incident. However, this patent is difficult to meet the needs of photoelectric and photothermal composite measurement, and it is also difficult to meet the needs of adjustable photoelectric attenuation multiples and calibration-free. Summary of the invention

[0004] In order to meet the needs of photoelectric and photothermal composite attenuation detection while solving the problem of adjustable and calibration-free photoelectric attenuation multiples, the present invention proposes a photoelectric and photothermal composite attenuation detection unit and a detection array based on solid scattering materials.

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

[0006] A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials comprises an energy absorber, a scattering sheet, a thermistor and a stud.

[0007] The energy absorber is an integral structure with a cylindrical exterior, and a conical hole, a sampling hole, and a cavity are sequentially arranged from top to bottom. The conical hole is a conical hole, and the sampling hole and the cavity are cylindrical holes. The central axes of the conical hole, the sampling hole, and the cavity coincide with the central axis of the energy absorber. A laser absorption coating is sprayed on the surface of the conical hole. The outer diameter of the cross section of the energy absorber is greater than the diameter of the upper bottom surface of the conical hole, the diameter of the upper bottom surface of the conical hole is greater than the diameter of the lower bottom surface, the diameter of the lower bottom surface of the conical hole is equal to the inner diameter of the sampling hole, and the inner diameter of the cavity is greater than the inner diameter of the sampling hole. A notch is arranged at the bottom of the energy absorber for fixing a thermistor, and the thermistor is used to measure the temperature of the energy absorber.

[0008] The scattering sheet is located in the cavity and is in the shape of a disc. Several sheets are stacked and the outer diameter matches the inner diameter of the cavity.

[0009] The lower part of the cavity is provided with an internal thread, which matches the external thread of the stud. The stud is installed in the internal thread. The stud is provided with an emission hole along the central axis. The emission hole is a cylindrical hole. The stud is used to fix the scattering sheet and emit laser.

[0010] The laser passes through the conical hole, sampling hole, and scattering plate in sequence and is emitted from the exit hole.

[0011] In the above-mentioned photoelectric and optical-thermal composite attenuation detection unit, the scattering plate is made of frosted glass material.

[0012] In the above-mentioned photoelectric and optical-thermal composite attenuation detection unit, the thermistor is a PT100 temperature measuring thermistor.

[0013] In the above-mentioned photoelectric and photothermal composite attenuation detection unit, the thermistor is bonded to the energy absorber through thermal conductive silicone.

[0014] In the above-mentioned photoelectric and optical-thermal composite attenuation detection unit, the energy absorber is made of copper, or aluminum or graphite.

[0015] A photoelectric and photothermal composite attenuation detection array based on solid scattering materials comprises several detection units, a support plate and a protective plate.

[0016] The central axes of the plurality of detection units are arranged in parallel, and are installed on the support plate and located between the support plate and the protection plate. The support plate and the protection plate are arranged in parallel.

[0017] The protection plate is provided with a protection plate entrance hole, and the support plate is provided with a support plate exit hole. The number of the protection plate entrance holes and the support plate exit holes is equal to the number of the detection units.

[0018] The laser passes through the entrance hole of the protection plate, the detection unit, and the exit hole of the support plate in sequence, and is emitted from the exit hole of the support plate.

[0019] The above-mentioned photoelectric and optical-thermal composite attenuation array detection array has a number of detection units greater than 2.

[0020] The above-mentioned photoelectric and optical-thermal composite attenuation array detection array has four detection units.

[0021] The beneficial effects of the present invention are:

[0022] A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials. The laser is coupled into the cavity through a sampling hole, and is emitted from the laser exit hole after being absorbed and scattered by the inside of the attenuation cylindrical cavity and multiple layers of frosted glass sheets. The light beam energy can be redistributed in a large range of space and has a homogenization effect. At the same time, good angle characteristics are guaranteed. Large-angle attenuation sampling can be achieved when the laser is obliquely incident, and a large attenuation of the laser power density can be met. The attenuation coefficient is positively correlated with the number of frosted glass sheets used. The more the number of frosted glass sheets, the greater the attenuation. The photoelectric attenuation multiple can be adjusted by adjusting the number of frosted glass sheets.

[0023] A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials. The temperature rise of the energy absorber is measured by a thermistor. The body heat capacity of the detection unit itself is considered as a fixed parameter. Therefore, the measurement of incident energy can be achieved.

[0024] A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials realizes calibration of the photoelectric attenuation multiple of the detection unit by measuring the energy of the energy absorber according to the energy of the detection unit being equal to the integral sum of the PT curve of the light power density.

[0025] A photoelectric and photothermal composite attenuation detection array based on solid scattering materials uses a support structure made of a material with very low thermal conductivity to reduce the thermal crosstalk between various detection units and ensure accurate measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of a photoelectric and photothermal composite attenuation detection unit according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the incident light scattering principle of the photoelectric and photothermal composite attenuation detection unit according to the first embodiment of the present invention;

[0028] Figure 3 This is the angle characteristic curve in the experimental results of incident light scattering principle verification of the photoelectric and photothermal composite attenuation detection unit in Example 1 of the present invention;

[0029] Figure 4 This is a curve of energy detection in the experimental results of incident light scattering principle verification of the photoelectric and photothermal composite attenuation detection unit in Example 1 of the present invention. Multiple measurements of the same detection unit have good repeatability.

[0030] Figure 5This is a curve of energy detection in the experimental results of incident light scattering principle verification of the photoelectric and photothermal composite attenuation detection unit in Example 1 of the present invention. Different detection units have good consistency in the same measurement;

[0031] Figure 6 The energy detection curve in the experimental results of incident light scattering principle verification of the photoelectric and photothermal composite attenuation detection unit in Example 1 of the present invention, and the temperature rise curves of the detection units made of different materials in the laser measurement at the same time;

[0032] Figure 7 The energy detection curve in the experimental results of incident light scattering principle verification of the photoelectric and photothermal composite attenuation detection unit in Example 1 of the present invention, and the temperature rise curve of the detection unit made of the same material in laser measurement at different times;

[0033] Figure 8 This is a schematic diagram of the structure of a photoelectric and photothermal composite attenuation detection array according to an embodiment of the present invention.

[0034] Figure numerals: 1. Energy absorber, 2. Scattering sheet, 3. Thermistor, 4. Stud, 5. Sampling hole, 6. Conical hole, 7. Cavity, 8. Internal thread, 9. Exit hole, 10. Protective plate, 11. Protective plate entrance hole, 12. Support plate, 13. Support plate exit hole, 14. Detection unit. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Embodiment 1

[0037] A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials, such as Figure 1As shown, it includes an energy absorber 1, a multi-layer frosted glass scattering sheet 2, a PT100 temperature measuring thermistor 3, and a stud 4. The energy absorber 1 is made of copper, aluminum, graphite or other materials. The energy absorber 1 has a conical hole 6, a small cylindrical sampling hole 5 and a large cylindrical cavity 7 along the incident laser. The surface of the conical hole 6 is sprayed with a laser absorption coating. The diameter of the small cylindrical sampling hole 5 is smaller than the diameter of the frosted glass scattering sheet 2 and the diameter of the large cylindrical cavity 7. The large cylindrical cavity 7 is filled with multi-layer frosted glass scattering sheets 2 as a large-multiple photoelectric attenuation channel for large-angle incidence. The overall photoelectric attenuation of the detection unit is achieved by adjusting the number of frosted glass scattering sheets 2. The multiple can be adjusted. A thread is processed on the wall surface of the tail of the large cylindrical cavity 7. A small cylindrical exit hole 9 is opened in the middle of the stud 4. There is an external thread on the outside, which is screwed with the internal thread 8 of the large cylindrical cavity 7. The above-mentioned small cylindrical sampling hole 5, the large cylindrical cavity 7 and the small cylindrical exit hole 9 of the stud 4 are coaxially arranged. A small notch is processed on the lower part of the energy absorber 1, and the size is determined according to the specific size of PT100. The energy absorber 1 and the PT100 thermistor 3 are bonded with thermally conductive silicone, so that PT100 can measure the temperature rise of the detection unit.

[0038] In the composite attenuation detection unit of the present invention, the energy measurement of the energy absorber 1 can realize the calibration of the photoelectric attenuation multiple. The specific implementation method is that the energy of the detection unit is equivalent to the integral sum of the PT curve of the optical power density, thereby realizing the calibration of the photoelectric attenuation multiple.

[0039] The energy measured by the energy absorber 1 realizes the correction of the integrated spot energy of the photodetector behind the exit hole of the detection unit. The relationship between the two is as follows:

[0040]

[0041] The left side of the equation is the energy measurement value of the energy absorber 1, and the right side is the energy value measured by the photodetector, where c is the specific heat capacity of the calorimetric unit, m is the mass of the calorimetric unit, ΔT is the temperature rise of the energy absorber 1, and P is the real-time power value measured by the photodetector. k is the photoelectric attenuation multiple, which is the amount to be corrected, t is time, t0 is the starting time, and t1 is the ending time, so:

[0042]

[0043] The value of k can be determined, and the intensity spatiotemporal distribution data and image of the light spot can be obtained through data processing, that is, the time information of the light spot can be obtained.

[0044] The principle of incident light scattering of the photoelectric and photothermal composite attenuation detection unit is as follows Figure 2 As shown, the incident laser travels along Figure 2After coupling into the cavity in the direction of the middle arrow, due to the diffuse transmission property of the frosted glass scattering sheet, 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 be reflected by the inner wall multiple times, which can ensure good angle characteristics. The actual measured angle characteristics are shown in the following figure. Figure 3 shown.

[0045] Figure 4-Figure 7 This is the energy detection curve in the experimental results of incident light scattering principle verification of the photoelectric and photothermal composite attenuation detection unit of the present invention. Figure 4 This is the result of multiple measurements of the same detection unit, which shows good repeatability. Figure 5 The results of different detection units in the same measurement show that different units have good consistency. Figure 6 The temperature rise curves of the detection units made of different materials in the laser measurement at the same time show that the temperature rise curves are significantly different due to the change in total heat capacity after the material is replaced. Therefore, different materials can be selected to make the detection unit according to the actual parameters of the incident laser. Figure 7 The temperature rise curve of the detection unit made of the same material during laser measurement at different times can be used to infer the absorbed energy based on the actual temperature rise curve, and then to correct the energy value of the integrated light spot measured by the photodetector.

[0046] A photoelectric and photothermal composite attenuation detection array, such as Figure 8 As shown, a plurality of the above-mentioned photoelectric and photothermal composite attenuation detection units 14 are installed on a large-area support plate 12, and a laser protection plate 10 is installed at the front end of the laser incidence, wherein a laser protection plate entrance hole 11 is processed on the laser protection plate 10, and the large-area support plate 12 is made of a material with extremely low thermal conductivity such as bakelite, and is processed with a laser support plate exit hole 13, thereby realizing array detection of large-area laser beams.

Claims

1. A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials, characterized in that: It comprises an energy absorber (1), a scattering sheet (2), a thermistor (3), and a stud (4); The energy absorber (1) is an integral structure, the outer part of which is cylindrical, and a conical hole (6), a sampling hole (5), and a cavity (7) are arranged in sequence from top to bottom; the conical hole (6) is a conical hole, the sampling hole (5) and the cavity (7) are all cylindrical holes, and the central axes of the conical hole (6), the sampling hole (5), and the cavity (7) coincide with the central axis of the energy absorber (1); a laser absorption coating is sprayed on the surface of the conical hole (6); the outer diameter of the cross section of the energy absorber (1) is greater than the diameter of the upper bottom surface of the conical hole (6), the diameter of the upper bottom surface of the conical hole (6) is greater than the diameter of the lower bottom surface, the diameter of the lower bottom surface of the conical hole (6) is equal to the inner diameter of the sampling hole (5), and the inner diameter of the cavity (7) is greater than the inner diameter of the sampling hole (5); a notch is arranged at the bottom of the energy absorber (1) for fixing the thermistor (3), and the thermistor (3) is used to measure the temperature of the energy absorber (1); The scattering sheet (2) is located in the cavity (7), is in the shape of a disc, and several sheets are stacked, with an outer diameter matching the inner diameter of the cavity (7); The lower part of the cavity (7) is provided with an internal thread (8), the internal thread (8) matches the external thread of the stud (4), the stud (4) is installed in the internal thread (8), the stud (4) is provided with an emission hole (9) along the central axis, the emission hole (9) is a cylindrical hole, and the stud (4) is used to fix the scattering sheet (2) and emit laser light; The laser light passes through the conical hole (6), the sampling hole (5), and the scattering plate (2) in sequence, and is emitted from the emission hole (9).

2. The photoelectric and photothermal composite attenuation detection unit according to claim 1, characterized in that: The scattering sheet (2) is made of frosted glass.

3. The photoelectric and photothermal composite attenuation detection unit according to claim 1, characterized in that: The thermistor (3) is a PT100 temperature measuring thermistor.

4. The photoelectric and photothermal composite attenuation detection unit according to claim 3, characterized in that: The thermistor (3) is bonded to the energy absorber (1) via thermally conductive silicone.

5. The photoelectric and photothermal composite attenuation detection unit according to claim 1, characterized in that: The energy absorber (1) is made of copper, aluminum or graphite.

6. A detection array comprising any one of the photoelectric and photothermal composite attenuation detection units of claims 1 to 5, characterized in that: It comprises a plurality of detection units (14), a support plate (12), and a protective plate (10); A plurality of detection units (14) are arranged with their central axes in parallel, mounted on a support plate (12), and located between the support plate (12) and a protective plate (10), wherein the support plate (12) and the protective plate (10) are arranged in parallel; The protective plate (10) is provided with a protective plate entrance hole (11), and the support plate (12) is provided with a support plate exit hole (13), and the number of the protective plate entrance holes (11) and the support plate exit holes (13) is equal to the number of the detection units (14); The laser light passes through the protection plate entrance hole (11), the detection unit (14), and the support plate exit hole (13) in sequence, and is emitted from the support plate exit hole (13).

7. The detection array according to claim 6, characterized in that: The number of the detection units (14) is greater than 2.

8. The detection array according to claim 6, characterized in that: The number of the detection units (14) is four.

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