A thz photodetector absolute spectral responsivity calibration device and method

Abstract

The invention provides a device and method for calibrating the absolute spectral response rate of a THz photoelectric detector. The method is implemented through a CO2 pumping gas THz laser device, a convergence lens, an attenuator, a main standard electricity replacement radiometer, an electric control displacement guide rail system, an isolation hood, an electric measuring instrument and a data acquisition and control system. The absolute spectral response rate of multiple frequency points of the THz photoelectric detector within the THz wave band can be calibrated, hence, the high-accuracy measurement problem with THz power is solved, and a powerful guarantee is provided for smooth operation of major engineering and development of THz devices and equipment.

Description

technical field [0001] The invention relates to the technical field of testing, in particular to a THz photodetector absolute spectral responsivity calibration device, and also relates to a THz photodetector absolute spectral responsivity calibration method. Background technique [0002] The absolute spectral responsivity refers to the ratio of the photocurrent (or voltage) output by the detector to the incident light power, which characterizes the ability of photoelectric conversion. The absolute spectral responsivity of the THz photodetector is calibrated for high-precision THz power measurement. premise. The application of THz technology in many fields has created the need to calibrate the absolute spectral responsivity parameters of THz photodetectors, which are specifically reflected in: calibration and comparison of THz light sources; calibration and comparison of THz detectors; in active security inspection systems and medical care Determine the upper limit of radiat...

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Problems solved by technology

[0004] Although PTB in Germany has established a THz optical power traceability and detector calibration device based on a cryogenic radiometer, and has carried out a THz detector absolute spectral responsivity calibration service, there is a 7% difference in the absorption of THz waves by the cryogenic radiometer cavity. Certainty, the measurement accuracy of the calibration device itself is difficult to be guaranteed. Obviously, for occasions with high requirements for measurement accuracy, the calibration effect of this device cannot meet the requirements

In addition, they use a quantum cascade laser as the THz light source, and the laser can only achieve output near the 2.5THz frequency point, so the calibration frequency point is single, and the calibration accuracy at other frequencies is more difficult to guarantee; the power stability of the light source is required in the calibration Reached a certain index, but they did not see the exact description of the output power stability index of the quantum cascade laser; the quantum cascade laser needs to operate in a low temperature environment, so the cooling facility also leads to a large calibration device, which is difficult to use and maintain

[0005] Up to now, there is still a lack of high-precision calibration methods for the absolute spectral responsivity of THz photodetectors at home and abroad, and it is impossible to achieve high-precision calibration of THz photodetectors, resulting in inconsistencies in the measurement of THz power by different detectors. It can meet the high-precision testing needs of THz devices and equipment in major projects and scientific research and production applications, which seriously limits the application of THz devices and systems in major projects and scientific research projects such as deep space exploration, remote sensing and space communication.

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