A photoelectric and photothermal composite attenuation detection unit and array based on a solid scattering material

Abstract

The present application relates to a kind of photoelectric photothermal composite attenuation detection unit and detection array based on solid scattering material, belong to photoelectric measurement technical field, solve the technical problem that photoelectric photothermal composite attenuation detection simultaneously detects unit photoelectric attenuation multiple adjustable and is free from calibration, its detection unit includes energy absorber, scattering sheet, thermistor, stud.Energy absorber is sequentially arranged conical hole, sampling hole, cavity from top to bottom, several pieces of the scattering sheet of stacking is located in cavity, stud is installed in the internal thread of cavity, stud sets exit hole, laser sequentially passes through conical hole, sampling hole, scattering sheet, and is emitted by exit hole.The detection array includes several detection units, support plate, protection plate.Protection plate sets protection plate incident hole, support plate sets support plate exit hole, and laser sequentially passes through protection plate incident hole, detection unit, and is emitted by support plate exit hole.The application is used for photoelectric photothermal composite attenuation detection.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic measurement equipment technology, specifically relating to an optoelectronic photothermal composite attenuation detection unit and detection array based on solid scattering materials. Background Technology

[0002] In high-energy laser parameter measurements, photodetector array sampling methods are frequently used to obtain the spatiotemporal distribution information of the power density of strong laser spots. Since the laser power density at the test location is generally high, it is necessary to reasonably attenuate the measured laser power density in actual testing to meet the measurement range of the photodetector.

[0003] Currently, the attenuation units used can generally only meet the needs of photoelectric measurement. Chinese invention patent CN102384783A discloses a high-energy laser semi-integrating sphere array attenuator, including a front panel, a rear panel, and several attenuation units arranged along the laser incident direction. Each attenuation unit includes a large-angle sampling cone hole on the front panel, a hemispherical cavity on the rear panel, and a laser exit hole located 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 located on opposite sides of the semi-integrating sphere cavity. The laser is coupled into the hemispherical cavity through the large-angle sampling cone hole, and after absorption and diffuse reflection by the semi-integrating sphere cavity, it exits through the laser exit hole, achieving a significant attenuation of the laser power density and meeting the attenuation sampling requirements when the laser is obliquely incident. However, this patent is insufficient to meet the needs of photoelectric and photothermal composite measurement, and it also fails to meet the requirements of adjustable photoelectric attenuation factor and calibration-free operation. Summary of the Invention

[0004] To meet the requirements of photoelectric and photothermal composite attenuation detection while solving the need for adjustable photoelectric attenuation factor and calibration-free operation, this invention proposes a photoelectric and photothermal composite attenuation detection unit and detection array based on solid scattering materials.

[0005] The technical solution adopted by this invention to solve its technical problem is:

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

[0007] The energy absorber is a monolithic structure with an external cylindrical shape. From top to bottom, it comprises a conical hole, a sampling hole, and a cavity. The conical hole is conical, while the sampling hole and cavity are cylindrical. The central axes of the conical hole, sampling hole, and cavity coincide with the central axis of the energy absorber. A laser-absorbing coating is sprayed onto the surface of the conical hole. The outer diameter of the energy absorber's cross-section is larger than the diameter of the upper surface of the conical hole, the diameter of the upper surface of the conical hole is larger than the diameter of the lower surface, the diameter of the lower surface of the conical hole is equal to the inner diameter of the sampling hole, and the inner diameter of the cavity is larger than the inner diameter of the sampling hole. A notch is provided at the bottom of the energy absorber for fixing a thermistor, which is used to measure the temperature of the energy absorber.

[0008] The scattering sheet is located inside the cavity, is circular in shape, and several sheets are stacked together, with the outer diameter matching 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, and the stud is provided with an emission hole along the central axis. The emission hole is a cylindrical hole, and the stud is used to fix the scattering plate and the laser emission.

[0010] The laser passes sequentially through a conical hole, a sampling hole, and a scattering plate before exiting through the emission hole.

[0011] In the aforementioned photoelectric and photothermal composite attenuation detection unit, the scattering sheet is made of frosted glass.

[0012] In the aforementioned photoelectric and photothermal composite attenuation detection unit, the thermistor is a PT100 temperature-sensing thermistor.

[0013] In the aforementioned photoelectric and photothermal composite attenuation detection unit, the thermistor is bonded to the energy absorber via thermally conductive silicone.

[0014] In the aforementioned photoelectric and photothermal composite attenuation detection unit, the energy absorber can be copper, aluminum, or graphite.

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

[0016] Several detection units are arranged in parallel along their central axes and mounted on a support plate, located between the support plate and the protective plate, which are arranged in parallel.

[0017] The protective plate is provided with a protective plate inlet hole, and the support plate is provided with a support plate outlet hole. The number of protective plate inlet holes and support plate outlet holes is equal to the number of detection units.

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

[0019] The aforementioned photoelectric and photothermal composite attenuation array detector array has more than two detection units.

[0020] The aforementioned photoelectric and photothermal composite attenuation array detector array has four detection units.

[0021] The beneficial effects of this invention are:

[0022] A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials is disclosed. A laser beam is coupled into the cavity through a sampling hole, and after absorption and volume scattering within the attenuation cylindrical cavity and multiple layers of frosted glass, it exits through the laser exit hole. This redistributes the beam energy over a large spatial range with a homogenization effect, while ensuring good angular characteristics. It can achieve large-angle attenuation sampling when the laser is obliquely incident, and can satisfy significant attenuation of laser power density. The attenuation coefficient is positively correlated with the number of frosted glass sheets used; the more sheets, the greater the attenuation. The photoelectric attenuation factor can be adjusted by regulating the number of frosted glass sheets.

[0023] A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials is disclosed. The temperature rise of the energy absorber is measured using a thermistor. Considering that the volumetric heat capacity of the detection unit itself is a fixed parameter, the incident energy can be measured.

[0024] A photoelectric and photothermal composite attenuation detection unit based on solid scattering materials is proposed. According to the principle that the energy of the detection unit is equal to the integral sum of the PT curves of the optical power density, the photoelectric attenuation factor of the detection unit is calibrated by measuring the energy of the energy absorber.

[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 thermal crosstalk between the detection units and ensure accurate measurement results. Attached Figure Description

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

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

[0029] Figure 4 The curve of energy detection in the experimental results of the incident light scattering principle verification of the photoelectric and photothermal composite attenuation detection unit in Embodiment 1 of the present invention shows that multiple measurements with the same detection unit have good repeatability.

[0030] Figure 5The curves for energy detection in the experimental results of the incident light scattering principle verification of the photoelectric and photothermal composite attenuation detection unit in Embodiment 1 of the present invention show that different detection units have good consistency in the same measurement.

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

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

[0033] Figure 8 This is a schematic diagram of the optoelectronic and photothermal composite attenuation detection array structure according to Embodiment 1 of the present invention.

[0034] Reference numerals: 1. Energy absorber, 2. Scatterer, 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 Implementation

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

[0036] Example 1

[0037] A photoelectric and photothermal recombination attenuation detection unit based on solid scattering materials, such as Figure 1As shown, the device includes an energy absorber 1, a multi-layer frosted glass diffuser 2, a PT100 temperature-sensing thermistor 3, and a stud 4. The energy absorber 1 is made of materials such as copper, aluminum, or graphite. Along the incident laser point, the energy absorber 1 has a conical aperture 6, a small cylindrical sampling aperture 5, and a large cylindrical cavity 7. A laser-absorbing coating is sprayed onto the surface of the conical aperture 6. The diameter of the small cylindrical sampling aperture 5 is smaller than the diameter of the frosted glass diffuser 2 and the diameter of the large cylindrical cavity 7. The large cylindrical cavity 7 is filled with multi-layer frosted glass diffusers 2 as a high-multiplier photoelectric attenuation channel for large-angle incident light. The overall photoelectric attenuation of the detection unit is achieved by adjusting the number of frosted glass diffusers 2. The multiplier is adjusted. The wall of the large cylindrical cavity 7 is threaded. The stud 4 has a small cylindrical emission hole 9 in the middle and external threads, which are screwed into the internal threads 8 of the large cylindrical cavity 7. The small cylindrical sampling hole 5, the large cylindrical cavity 7 and the small cylindrical emission hole 9 of the stud 4 are coaxially arranged. The lower part of the energy absorber 1 is machined with a small notch, the size of which is determined according to the specific size of the PT100. The energy absorber 1 and the PT100 thermistor 3 are bonded with thermally conductive silicone. Thus, the 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 factor. Specifically, the energy of the detection unit is equal to the sum of the integrals of the PT curve of the optical power density, thereby realizing the calibration of the photoelectric attenuation factor.

[0039] The energy measured by energy absorber 1 is used to correct the integrated spot energy of the photodetector after the exit aperture of the detection unit. The relationship between the two is as follows:

[0040]

[0041] The left side of the equation represents the measured energy value of energy absorber 1, and the right side represents the energy value measured by the photodetector. Here, c is the specific heat capacity of the calorimeter unit, m is the mass of the calorimeter unit, ΔT is the temperature rise of energy absorber 1, and P is the real-time power value measured by the photodetector. k is the photoelectric attenuation factor, which is a quantity to be corrected. t is time, t0 is the start time, and t1 is the end time. Therefore:

[0042]

[0043] The value of k can be determined from this, and the spatiotemporal distribution data and image of the light spot intensity 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 in the photoelectric and photothermal composite attenuation detection unit is as follows: Figure 2 As shown, the incident laser travels along... Figure 2After the light beam is coupled into the cavity in the direction of the middle arrow, due to the diffuse transmission properties of the frosted glass diffuser, the scattered light intensity I(θ) is distributed in space according to Lambert's cosine law, i.e., 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 with angle θ. Scattering can redistribute the beam energy over a large spatial range and has a homogenizing effect. Regardless of the incident angle, the beam will undergo multiple reflections from the inner wall, ensuring good angular characteristics. The actual measured angular characteristics are as follows... Figure 3 As shown.

[0045] Figures 4-7 The curve representing the energy detection in the experimental results verifying the incident light scattering principle of the photoelectric and photothermal composite attenuation detection unit of this invention is shown. Figure 4 The results, obtained from multiple measurements using the same detection unit, demonstrate excellent repeatability. Figure 5 The results from different detection units in the same measurement demonstrate that the different units exhibit good consistency. Figure 6 The temperature rise curves of detection units made of different materials during the same laser measurement time show that the temperature rise curves differ significantly due to changes in total heat capacity and other parameters after material replacement. Therefore, different materials can be selected to manufacture the detection unit based on the actual incident laser parameters. Figure 7 The temperature rise curves of the detection unit made of the same material at different times during laser measurement can be used to deduce the absorbed energy based on the actual temperature rise curves, and then correct the energy value of the integrated spot measured by the photodetector.

[0046] A photoelectric and photothermal composite attenuation detection array, such as Figure 8 As shown, multiple photoelectric and photothermal composite attenuation detection units 14 are installed on the large-area support plate 12, and a laser protection plate 10 is installed at the laser incident front end. The laser protection plate 10 is provided with a laser protection plate incident hole 11. The large-area support plate 12 is made of a material with extremely low thermal conductivity, such as bakelite, and is provided with a laser support plate exit hole 13. This enables the array detection of a large-area laser beam.

Claims

1. A solid-scattering material based photo-opto-thermo-composite attenuation detection array, characterized in that, It includes several detection units (14), a support plate (12), and a protective plate (10). Several detection units (14) are arranged in parallel along their central axes and installed on a support plate (12), located between the support plate (12) and the protective plate (10), which are arranged in parallel. The protective plate (10) is provided with a protective plate inlet hole (11), and the support plate (12) is provided with a support plate outlet hole (13). The number of protective plate inlet holes (11) and support plate outlet holes (13) is equal to the number of detection units (14). The laser passes sequentially through the protective plate inlet hole (11), the detection unit (14), and the support plate outlet hole (13), and is emitted from the support plate outlet hole (13); The support plate (12) is made of a material with low thermal conductivity; The detection unit (14) includes an energy absorber (1), a diffuser (2), a thermistor (3), and a stud (4). The energy absorber (1) is an integral structure with a cylindrical exterior. From top to bottom, it is provided with a conical hole (6), a sampling hole (5), and a cavity (7). The conical hole (6) is a conical hole, while the sampling hole (5) and the cavity (7) are both cylindrical holes. 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). The surface of the conical hole (6) is coated with a laser absorption coating. The outer diameter of the cross-section of the energy absorber (1) is larger 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 larger 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 larger than the inner diameter of the sampling hole (5). A notch is provided at the bottom of the energy absorber (1) for fixing a thermistor (3), which is used to measure the temperature of the energy absorber (1). The scattering sheet (2) is located inside the cavity (7), is circular in shape, and several sheets are stacked together, with the outer diameter matching the inner diameter of the cavity (7); The cavity (7) is provided with an internal thread (8) at the bottom. 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 exit hole (9) along the central axis. The exit hole (9) is a cylindrical hole. The stud (4) is used to fix the scattering plate (2) and the laser emission. The laser passes through the conical hole (6), the sampling hole (5), and the scattering plate (2) in sequence, and is emitted from the exit hole (9).

2. The opto-electric photothermal complex extinction probe array of claim 1, wherein, The diffuser (2) is made of frosted glass.

3. The opto-electric photothermal complex extinction probe array of claim 1, wherein, The thermistor (3) is a PT100 temperature measuring thermistor.

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

5. The opto-electric photothermal complex extinction probe array of claim 1, wherein, The energy absorber (1) can be made of copper, aluminum, or graphite.

6. The opto-electric photothermal complex extinction probe array of claim 1, wherein, The support plate (12) is made of bakelite.

7. The array of claim 1, wherein The number of the detection units (14) is greater than 2.

8. The array of claim 1, wherein, The number of the detection units (14) is 4.

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