Novel calibration optical path of cryogenic radiometer

We introduce a novel calibration optical path of the cryogenic radiometer, which can avoid the repeated dismounting measurement and eliminate the negative influence of Brewster window effect on calibration result. The novel calibration optical path is used to calibrate the absolute spectral responsivity of the standard transfer detector at 633 nm, the results of which are compared with the ones of the previous structure. It is shown that comparing the previous results to the structure optimizati