High-accuracy middle-infrared-band absolute spectral responsivity calibrating device

Abstract

The invention provides a high-accuracy middle-infrared-band absolute spectral responsivity calibrating device which comprises a middle-infrared tunable optical parametric oscillator, an acoustic optical modulator, a space filter, a middle-infrared laser power stabilization system, a photoelectric detector vacuum chamber, a low-temperature radiometer system and a vacuum set. After output laser of the middle-infrared tunable optical parametric oscillator passes through the acoustic optical modulator, the output laser enters the space filter to optimize beam quality of the laser and is divided into two beams after passing through a beam splitting piece, one laser beam enters the laser power stabilization system and is used for outputting a voltage signal to control a drive signal on the acoustic optical modulator, and the other laser beam enters the photoelectric detector vacuum chamber and the low-temperature radiometer system and is used for calibrating absolute spectral responsivity of a photoelectric detector. According to the technical scheme, output wavelengths of a laser device can be continuously regulated within the range of 1.3 micrometers-2 micrometers and 2.2 micrometers-4.7 micrometers, a calibrated wavelength point of the absolute spectral responsivity can be increased at will, and measurement accuracy is improved.

Description

technical field [0001] The invention belongs to the technical field of infrared band absolute spectral responsivity calibration, and in particular relates to a high-precision mid-infrared band absolute spectral responsivity calibration device. Background technique [0002] The cryogenic absolute radiometer is the highest precision measurement standard for optical radiation power calibration. It integrates advanced technologies such as vacuum, superconductivity, liquid nitrogen and liquid helium double-layer cold shielding, and equates optical radiation power measurement to electrical power measurement. Its measurement accuracy Reached the order of magnitude better than 10-5. Cryogenic radiometers play a fundamental and key role in the fields of space remote sensing, climate monitoring, environmental monitoring, optical radiation measurement, and communications. [0003] In recent years, foreign metrology institutions represented by NIST in the United States and NPL in the U...

AI Technical Summary

Problems solved by technology

Compared with photon detectors, thermal detectors not only have low response rate and long response time, but also have poor stability, which will introduce large measurement uncertainty

[0006] At present, there are very few studies on the absolute spectral responsivity calibration of photodetectors in the 2.5 μm ~ 5 μm mid-infrared band at home and abroad. The common shortcomings of the few solutions include: (1) The laser used in the absolute spectral responsivity calibration The output wavelength of the source is a single wavelength, so the change of the calibration wavelength of the absolute spectral responsivity can only be realized by switching the laser light source, and the calibration wavelength can only be several discrete fixed wavelength points

(2) The standard detectors used in the calibration of absolute spectral responsivity in the mid-infrared band are thermal detectors such as pyroelectric or thin-film thermopiles. Compared with photon detectors, thermal detectors have relatively low responsivity and relatively short response time. In addition, the performance of thermal detection is greatly affected by the shape, size and production process of the device, resulting in poor stability of thermal detectors. Measurement uncertainty will be introduced in the calibration process of absolute spectral responsivity, which will affect low temperature radiation. Accuracy of the value transfer of the meter

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