Infrared weak light radiation calibration device and calibration method for photoelectric reconnaissance equipment

Abstract

This invention discloses an infrared weak light radiation calibration device and method for optoelectronic reconnaissance equipment, belonging to the field of optoelectronic technology. The calibration device includes an infrared light source system, an infrared beam transmission channel, the optoelectronic reconnaissance equipment under test, a vacuum interface, a vacuum enclosure, a first off-axis parabolic reflector, a field stop, a second off-axis parabolic reflector, a filter, a third off-axis parabolic reflector, a blocking impurity band detector, a pulse tube cooler, and a vacuum pump unit. The blocking impurity band detector of this invention has advantages such as high sensitivity, large array size, wide detection spectrum, and fast response speed; it can achieve picowatt-level optical radiation power measurement and calibration, and its unique performance is widely used in fields such as space imaging; using the blocking impurity band detector as a value transfer detector can improve measurement accuracy, reduce the influence of standard light source power fluctuations, and improve measurement accuracy.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic technology, specifically relating to an infrared weak light radiation calibration device and calibration method for optoelectronic reconnaissance equipment. Background Technology

[0002] High-sensitivity optoelectronic reconnaissance equipment uses infrared detectors to measure weak light radiation. The infrared weak light radiation testing system provides an infrared collimated beam. The infrared irradiance of the testing system has become the most critical parameter for testing the detection sensitivity and other technical indicators of infrared detection equipment. The accuracy and reliability of its value are directly related to the performance indicators of high-sensitivity optoelectronic reconnaissance equipment.

[0003] Currently, the KVACC low-temperature background infrared radiation testing system developed by the U.S. Air Force Research Laboratory boasts the best performance in measuring weak infrared radiation. The National Institute of Standards and Technology (NIST) traces weak infrared radiation back to cryogenic radiometers for metrological traceability, and uses Fourier transform spectroscopy to analyze the radiation characteristics at different wavelengths, achieving a spectral range of 3μm to 20μm; the irradiance measurement range is 10... -9 W / cm 2 / μm~10 -15 W / cm 2 / μm, with measurement uncertainty reaching 3% to 5%.

[0004] my country's research in the field of low-temperature weak infrared radiation testing systems started relatively late, but with the needs of national defense construction, significant research results have been achieved. However, due to limitations in technology and funding, there is still a considerable gap compared to foreign countries. The Changchun Institute of Optics, Fine Mechanics and Physics of the Chinese Academy of Sciences has developed the ZM3000 optical remote sensor space environment simulation test equipment based on a blackbody as the standard radiation source. Due to the lack of calibration capabilities for weak infrared radiation in China, the magnitude of weak infrared radiation signals can only be analyzed through theoretical calculations, and accurate and reliable calibration data cannot be provided.

[0005] High-sensitivity optoelectronic reconnaissance equipment is carried as a payload on remote sensing satellites, reconnaissance drones, long-range rockets, and other equipment for long-term patrol flights over targets, reconnaissance and surveillance, damage assessment, and communication relay. Currently, high-sensitivity optoelectronic reconnaissance equipment mainly uses blackbodies as standard radiation sources for calibration, which has the following problems: (1) Blackbody emissivity calibration is difficult and surface uniformity measurement accuracy is poor, which cannot meet the high-accuracy calibration and quantitative application requirements of optoelectronic reconnaissance equipment; (2) Optoelectronic reconnaissance equipment mainly collects weak light radiation, and when using blackbodies for calibration, the thermal radiation of the space environment has a significant impact on the measurement results. Summary of the Invention

[0006] In view of the above-mentioned technical problems existing in the prior art, the present invention proposes an infrared weak light radiation calibration device and calibration method for photoelectric reconnaissance equipment. The design is reasonable, overcomes the shortcomings of the prior art, and has good effect.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An infrared weak light radiation calibration device for optoelectronic reconnaissance equipment includes an infrared light source system, an infrared beam transmission channel, the optoelectronic reconnaissance equipment under test, a vacuum interface, a vacuum cover, a first off-axis parabolic reflector, a field aperture, a second off-axis parabolic reflector, a filter, a third off-axis parabolic reflector, a blocking impurity zone detector, a pulse tube refrigerator, and a vacuum pump unit.

[0009] The infrared light source system is a low-temperature blackbody light source, configured to provide weak infrared radiation for calibration.

[0010] The infrared beam transmission channel is a vacuum double-layer corrugated tube, configured to isolate interference from external stray light;

[0011] The vacuum hood is configured to provide a low-temperature vacuum environment for the detector and optical transmission channel to block impurities, isolate stray light, and improve the measurement signal-to-noise ratio.

[0012] The first off-axis parabolic reflector, the second off-axis parabolic reflector, and the third off-axis parabolic reflector are configured to reflect and converge weak infrared light radiation to ensure that the light radiation is transmitted to the detector that blocks the impurity zone.

[0013] The field stop is configured to shield stray light;

[0014] The filter is configured to filter light radiation of different wavelengths;

[0015] The barrier impurity band detector is configured for weak infrared radiation measurement and outputs a current signal.

[0016] The pulse tube refrigerator is configured to provide a cooling source for the blockage impurity belt detector and optical transmission system;

[0017] The vacuum pump unit is configured to evacuate the measurement system, reduce the interference of water molecules on infrared radiation, and ensure a vacuum environment for measuring weak light radiation.

[0018] Furthermore, this invention also mentions a method for calibrating the infrared weak light radiation of an optoelectronic reconnaissance device. This method employs an infrared weak light radiation calibration device for an optoelectronic reconnaissance device as described above, and specifically includes the following steps:

[0019] Step 1: Power on the device and lower the temperature of the infrared weak light radiation calibration device to the working temperature range of 3K~10K for the detector with the impurity blocking band, and then preheat it.

[0020] Step 2: Adjust the position of the infrared light source system so that the center of the output light spot after the light radiation passes through the infrared light source system can accurately illuminate the center position of the detector blocking the impurity zone.

[0021] Step 3: Adjust the rotating filter to select light radiation of a specific wavelength λ0 to enter the infrared weak light radiation calibration device, and measure the light radiation power P1(λ0);

[0022] Step 4: Move the photoelectric reconnaissance device under test into the optical path, adjust the position and tilt angle of the photoelectric reconnaissance device under test so that the optical path is perpendicularly incident on the center of the photosensitive surface, and record the measured optical power value P2(λ0) of the photoelectric reconnaissance device under test.

[0023] Step 5: Repeat steps 3 and 4 two or more times, and calculate the average value. and Calculate the correction factor of the photoelectric reconnaissance device under test according to formula (1):

[0024]

[0025] In the formula:

[0026] R(λ0)——Correction coefficient of the photoelectric reconnaissance equipment being calibrated at wavelength λ0, in units of 1;

[0027] —The average light radiation power of the infrared weak light radiation calibration device at wavelength λ0, in W;

[0028] —Measurement values ​​of the photoelectric reconnaissance equipment being calibrated, in W.

[0029] The beneficial technical effects of this invention are as follows:

[0030] 1) Blocking impurity band detectors, also known as BIB detectors, have high sensitivity (NEP up to 10). -16 W / Hz -1 / 2 It features a large array size (1024×1024), a wide detection spectrum (wavelength coverage of 2–40 μm), and a fast response speed (time constant 10). -10 The advantages of s) are that it can achieve the measurement and calibration of optical radiation power at the picometer level, and its unique performance is widely used in fields such as space imaging;

[0031] 2) Using a blocking impurity band detector as a value transfer detector can improve measurement accuracy, reduce the impact of standard light source power fluctuations, and improve measurement accuracy. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the infrared weak light radiation calibration device of the photoelectric reconnaissance equipment of the present invention;

[0033] Among them, 1-infrared light source system; 2-infrared beam transmission channel; 3-the photoelectric reconnaissance equipment under test; 4-vacuum interface; 5-vacuum cryogenic enclosure; 6-first off-axis parabolic reflector; 7-aperture stop; 8-second off-axis parabolic reflector; 9-filter; 10-third off-axis parabolic reflector; 11-blocking impurity zone detector B detector; 12-pulse tube refrigerator; 13-vacuum pump unit. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0035] like Figure 1 As shown, an infrared weak light radiation calibration device for photoelectric reconnaissance equipment includes an infrared light source system 1, an infrared beam transmission channel 2, the photoelectric reconnaissance equipment under test 3, a vacuum interface 4, a vacuum cover 5, a first off-axis parabolic reflector 6, a field stop 7, a second off-axis parabolic reflector 8, a filter 9, a third off-axis parabolic reflector 10, a blocking impurity zone detector 11, a pulse tube refrigerator 12, and a vacuum pump unit 13.

[0036] The infrared light source system 1 is a low-temperature blackbody light source used to provide weak infrared radiation for calibration; the infrared beam transmission channel 2 is a vacuum double-layer bellows used to isolate interference from external stray light; the vacuum hood 5 provides a low-temperature vacuum environment for the impurity band detector and the optical transmission channel, isolating stray light and improving the measurement signal-to-noise ratio; the first off-axis parabolic reflector 6, the second off-axis parabolic reflector 8, and the third off-axis parabolic reflector 10 are used to reflect and converge weak infrared light radiation, ensuring that the light radiation is transmitted to the impurity band detector 11; the field stop 7 is used to shield stray light; the filter is used to filter light radiation of different wavelengths; the impurity band detector 11 is used for weak infrared light radiation measurement, outputting a current signal, and has high sensitivity (NEP up to 10). -16 W / Hz -1 / 2 It features a large array size (1024×1024), a wide detection spectrum (wavelength coverage of 2μm~40μm), and a fast response speed (time constant 10). -10 The advantages of s); the pulse tube refrigerator 12 is used to provide a cold source for the BIB detector and optical transmission system; the vacuum pump unit 13 is used to evacuate the measurement system, reduce the interference of water molecules on infrared radiation, and ensure a vacuum environment for weak light radiation measurement.

[0037] An infrared weak light radiation calibration device for optoelectronic reconnaissance equipment utilizes a blocking impurity band (BIB) detector as a measurement transfer detector to achieve the measurement transfer of picowatt-level weak light radiation power. A pulse tube cryostat provides a deep cryogenic cold source, filters select the wavelength of light radiation, and two off-axis parabolic mirrors converge the incident beam onto the BIB detector surface for light radiation power detection. Calibration of the optoelectronic reconnaissance equipment is achieved by switching the same beam into the device. The calibration device can be traced back to a cryogenic radiometer, enabling traceability of light radiation measurements. This research developed an optical radiation calibration device based on a blocking impurity band (BIB) detector, leveraging the high sensitivity of the BIB detector to weak infrared radiation to achieve high-precision calibration of highly sensitive optoelectronic reconnaissance equipment. The blocking impurity band (BIB) detector has high sensitivity (NEP up to 10). -16 W / Hz -1 / 2 It features a large array size (1024×1024), a wide detection spectrum (wavelength coverage of 2–40 μm), and a fast response speed (time constant 10). -10 The advantages of s).

[0038] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for calibrating infrared weak light radiation of an optoelectronic reconnaissance device, characterized in that: An infrared weak light radiation calibration device for photoelectric reconnaissance equipment is adopted. The device includes an infrared light source system, an infrared beam transmission channel, the photoelectric reconnaissance equipment under test, a vacuum interface, a vacuum hood, a first off-axis parabolic reflector, a field aperture, a second off-axis parabolic reflector, a filter, a third off-axis parabolic reflector, a blocking impurity zone detector, a pulse tube refrigerator, and a vacuum pump unit. The infrared light source system is a low-temperature blackbody light source, configured to provide weak infrared radiation for calibration. The infrared beam transmission channel is a vacuum double-layer corrugated tube, configured to isolate interference from external stray light; The vacuum hood is configured to provide a low-temperature vacuum environment for the detector and optical transmission channel to block impurities, isolate stray light, and improve the measurement signal-to-noise ratio. The first off-axis parabolic reflector, the second off-axis parabolic reflector, and the third off-axis parabolic reflector are configured to reflect and converge weak infrared light radiation to ensure that the light radiation is transmitted to the detector that blocks the impurity zone. The field stop is configured to shield stray light; The filter is configured to filter light radiation of different wavelengths; The barrier impurity band detector is configured for weak infrared radiation measurement and outputs a current signal. The pulse tube refrigerator is configured to provide a cooling source for the blockage impurity belt detector and optical transmission system; The vacuum pump unit is configured to evacuate the measurement system, reduce the interference of water molecules on infrared radiation, and ensure a vacuum environment for measuring weak light radiation. The method specifically includes the following steps: Step 1: Power on the device and lower the temperature of the infrared weak light radiation calibration device to the working temperature range of 3K~10K for the detector with the impurity blocking band, and then preheat it. Step 2: Adjust the position of the infrared light source system so that the center of the output light spot after the light radiation passes through the infrared light source system can accurately illuminate the center position of the detector blocking the impurity zone. Step 3: Adjust the rotating filter to select a specific wavelength. The light radiation enters the infrared weak light radiation calibration device, and the light radiation power P1 is measured. ); Step 4: Move the photoelectric reconnaissance device under test into the optical path, adjust the position and tilt angle of the device so that the light path is perpendicular to the center of the photosensitive surface, and record the measured optical power value P2 of the device under test. ); Step 5: Repeat steps 3 and 4 two or more times, and calculate the average value. and The correction factor of the tested photoelectric reconnaissance equipment is calculated according to formula (1): （1）； In the formula: —The optoelectronic reconnaissance equipment under investigation Correction factor for wavelength point, in units of 1; —Infrared weak light radiation calibration device in Average optical radiant power at a wavelength, in W; —Measurement values ​​of the photoelectric reconnaissance equipment being calibrated, in W.

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