The Fourier transform spectrometer without slit has the advantages of high radiation throughput and high spatial resolution. It can be used for detecting more details of the spectral and spatial information. We present the initial structure of the collimator and objective based on the analysis of the principle of the Fourier transform spectrometer. Then the collimator and objective are optimized by Zemax. The MTF of the cut-off frequency is great than 0.7. The tunable lateral shearing splitter is used as the interferometer, which makes the system more compact compared with the system using Sagnac lateral shearing splitter. The method to calculate the geometric dimension of the splitter is presented. Then the complete Fourier transform spectrometer is designed. The MTF of the cut-off frequency is great than 0.6. And the largest RMS of the spot is less than 6μm.
The technology of interferometric imaging spectrometer can detect spatial information and spectral information of targets simultaneously. It has been the research hotpot because of its advantages of high throughput, high spectral resolution, high spatial resolution and so on. In order to obtain the spectral images of scene at different distance, a system of interferometric imaging spectrometer is presented, which consists of two imaging lens, a collimating lens, a Sagnac transverse shearing splitter and a detector. Based on the analysis of the optical paths and structure of spectrometer, system parameters of interferometric imaging spectrometer were researched, especially the ones of the transverse shearing splitter, incident plane width, mirror offset, optical parallelism error, and the clear aperture of the imaging lens and collimating lens . Optimal system parameters were given by discussing the relationship of parameters including transverse shearing splitter, detection distance, imaging lens, collimating lens and detector. Experimental prototype is set up to verify the impact of the error of system parameters on the imaging properties.