Analysis of signal-to-noise ratio of an ultra-compact static polarization interference imaging spectrometer

Abstract

Based on radiometry, electromagnetism and polarization theories and Fourier transform spectroscopy, an in-depth study is conducted on the signal-to-noise ratio (SNR) of the self-developed ultra-compact static polarization interference imaging spectrometer (USPIIS) both theoretically and experimentally. The theoretical equations of its SNR are deduced. Under the paraxial approximation, the curved line of the SNR with incidence angle changing is given via computer simulation. How the polarizing directions affect the SNR of the USPIIS, which is a particular sign of the polarization interference imaging spectrometer, is closely studied. When modulation depth equals 0.6, 0.7, 0.8, 0.9 and 1.0, the curved lines of the SNR with changing polarizing directions are given; after that, the optimum value is proposed. Under optimum conditions, the changing laws of SNR with the detector element are obtained, the same as the theoretical prediction. The theoretical and experimental results both indicate that the novel imaging spectrometer has the advantages of high throughput and high SNR under the condition of high modulation depth, which is suitable for aeronautics and space remote sensing and weak signal testing.