Spectral responsivity calibration of a polarization remote sensor based on a supercontinuum laser and monochromator

Abstract

ABSTRACT Relative spectral responsivity is a basic parameter for detecting and evaluating the in-band response non-consistency of the channel polarization remote sensor (CPRS) in laboratory calibration. In this paper, a spectrally resolved calibration facility was assembled for the calibration of relative spectral responsivity by using novel supercontinuum laser and monochromator (SLM). Taking three polarization channels of 490 nm, 670 nm and 910 nm as examples, the relative spectral responsivity of the CPRS was obtained from two calibration sources, respectively – the SLM and the monochromatic light from SLM steered into integrating sphere. Before measuring the relative spectral responsivity of the CPRS, the degree of linear polarization (DOLP) and the polarization orientation angle of two calibration sources were acquired by the spectral polarization analyser (SPOLA). The test result indicates that the output light of the latter calibration source has less the DOLP and smaller range of variation in the polarization orientation angle. In the experiment of measuring the relative spectral responsivity, while using monochromator as calibration source, the in-band response non-consistency of the three channels were 0.91%, 4.25% and 1.06%, respectively. Correspondingly, while using monochromatic light steered into integrating sphere, there were 0.15%, 0.47% and 0.57%, respectively. It can be concluded that SLM equipped integrating sphere sharply decreased the impact from the polarization characteristic of the source and could be effectively applied in the relative spectral responsivity calibration of CPRS.