Detection of Room-Temperature Blackbody Radiation by Parametric Upconversion

Abstract
Room‐temperature thermal (blackbody) radiation has been detected via parametric‐frequency upconversion. Thermal radiation was mixed with the output of a Nd:YAG laser in proustite. The wavelength of the radiation upconverted was varied from 6.5 to 12.5 μ by rotating the proustite 20 deg. The spectral width of the blackbody radiation accepted by the upconverter was approximately 0.7 μ.