Acta Optica Sinica, Volume. 41, Issue 10, 1029001(2021)
Stray Light Suppression in Sweep Mirror Field-Widened Space-Borne Fourier Transform Imaging Spectrometer
The field widening of a sweep mirror field-widened Fourier transform imaging spectrometer is achieved by adding a sweep mirror before its optical system. However, the addition of the sweep mirror causes the cross distribution of rays from different fields and different channels, which presents a difficulty in the suppression of stray light, and thus the traditional stray light suppression design is no longer valid. To solve this problem, a new design of stray light suppression is proposed. Based on the stray light suppression design, the point source transmittance (PST) stimulation and analysis of the visible and near-infrared optical system and the shortwave infrared optical system is presented for the sweep mirror at different field of view locations of 0°, 15°, and -15°. The analysis results show that as for all sweep mirror locations, the PST along the spatial direction and spectral direction at 0.5° off-field angle can be reduced to 10 -3. Based on the observation mode, the signal source and stray light source of the on-orbit imaging spectrometer are analyzed. In addition, based on the PST stimulation results, the stray light irradiance at the focal plane is studied and the signal-to-stray ratio is calculated. It shows that the signal-to-stray ratio of the visible and near-infrared optical system is 0.1% and that of the shortwave infrared optical system is 0.6%. The results indicate that the proposed stray light suppression method is effective and can meet the requirement of the space-borne imaging spectrometer.
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Zhinan Zhang, Libo Li, Chunbo Zou, Xiongbo Hao, Jian Sun, Xuebin Liu, Pengchong Wang, Jie Liu. Stray Light Suppression in Sweep Mirror Field-Widened Space-Borne Fourier Transform Imaging Spectrometer[J]. Acta Optica Sinica, 2021, 41(10): 1029001
Category: Scattering
Received: Oct. 29, 2020
Accepted: Dec. 8, 2020
Published Online: May. 8, 2021
The Author Email: Li Libo (lilibo@opt.ac.cn)