The parameters for characterizing far-infrared video detectors

It is pointed out that responsivity to radiation power, and noise equivalent power, is not a good parameter to characterize far-infrared video detectors when the size of the detector components is not much greater than operating wavelengths. Based on the theory of the angular spectrum of plane waves, it is shown that responsivity to the flux density, antenna pattern, and noise equivalent flux density, is a parameter for characterizing the performances of far-infrared video detectors for radiometric applications. Methods of measuring these parameters are briefly described. Typical measured results of InSb far-infrared hot electron bolometers are given.