Spectral power and irradiance responsivity calibration of InSb working-standard radiometers

New, improved-performance InSb power-irradiance meters have been developed and characterized to maintain the National Institute of Standards and Techn ology (NIST) spectral responsivity scale between 2 and 5.1 mum. The InSb ra diometers were calibrated against the transfer-standard cryogenic bolometer that is tied to the primary-standard cryogenic radiometer of the NIST. The InSb radiometers serve as easy-to-use working standards for routine spectr al power and irradiance responsivity calibrations. The spectral irradiance responsivities were derived from the spectral power responsivities by use o f the measured area of the apertures in front of the InSb detectors. (C) 20 00 Optical Society of America. OCIS codes: 040.0040, 040.3060, 040.5350, 12 0.5630, 230.5160.