Radiometric calibration facility for optical sensors using wavelength-tunable laser

A radiometric calibration facility for optical sensors was developed using wavelength-tunable lasers as the light sources and a silicon photodiode as the standard detector of radiometric responsivities. This facility enabled us to calibrate the responsivities that were previously impossible to measure, such as the relative spectral responsivity of an optical sensor with a large aperture, and the linearity continuously over four orders of dynamic range. This paper describes an overview of this facility and its characteristics.