A New Spectral Responsivity Calibration Comparator of InGaAs photodiode Based on Cryogenic Radiometer Fundamental at the National Institute of Metrology of China

摘要

A new comparator facility for spectral responsivity calibration of InGaAs photodiode based on cryogenic radiometer fundamental has been set up at the National Institute of Metrology of China (NIM). The comparator employed a stable supercontinuum light source, a prime-grating monochromator, a reliable 5-axis stage and some necessary optics as its main construction components. The supercontinuum source, monochromator and some beam path were also commonly utilized by the cryogenic radiometer, which was designed to minimize the deviations to the calibration procedure introduced by these components. The spectral responsivity of the InGaAs photodiode in the spectral range 900nm-1600nm was determined. The repeatability obtained by this new comparator is one decade better than that of former InGaAs measurement facility. NIM has been better supported to finish the measurements of transfer detectors of key comparison of CCPR-K2.a.2016 by this new and accuracy comparator.