Optical design of VIS-SWIR imaging spectrometer based on acousto-optic tunable filter

In order to widen the spectral coverage of imaging spectrometer based on Acousto-optic tunable filer (AOTF) from 400 nm to 2500 nm, a new configuration of all reflective fore-optics is proposed. The primary and secondary mirrors are used as common objective for visible and short-wave infrared channels, and then there are two independent tertiary mirrors in each channel. This configuration not only solves the problems caused by multi-view observation in traditional systems, but also meets the aperture requirements of both AOTFs to make them work in peak performance. The initial structure parameters is calculated by simultaneous Seidel aberration equations. The final design results validate the availability of this configuration in the AOTF based imaging spectrometer with two channels.