Study And Design Of Fore Optical System Of Static Infrared Imaging Spectrometer

Temporal spatial modulation imaging Fourier transform spectrometer is studied inthis paper which using the MEMS micro multi-step reflect mirror instead of thetraditional moving mirror instrument in Michelson interferometer, acquire images ofthe target object, and at the same time, get the intensity distribution in spatial domaindiscrete sampling caused by objects path difference, namely the spectrum informationof objects, forming a three-dimensional data cube on the target object, in the objectdetection and object recognition field has broad prospects of development.Fore optical system is an important part of imaging spectrometer, and its mainrole is to be infinitely distant objects clearly imaged in the plane mirror and the ladderof the micro mirror at the same time, to ensure that the system can form interferencefringes and stable, so that the main light field perpendicular to the incident planemirror. The main contents of this dissertation include：(1) According to the characteristics of the working principle of time-spacemodulated Fourier transform imaging spectrometer and infrared optical system, theoptical system between the infrared detectors and pre contact are analyzed,considering the pre imaging system for imaging spectrometer working performanceinfluence, proposed the pre imaging optical system parameters.(2)According to the geometric imaging principle, lists the telecentric systemparameter equations, by solving the equations which the reasonable solution, achieved telecentric beam path condition, realize the telecentric structure.(3) The off-axis aberrations of sheet caused the beam splitter and thecompensating plate, and free surface based on aberration theory research, put forwardthe methods of solving off-axis aberrations of the system. Adopted the method ofcorrection based on cylindrical and Zernike faces in order to improve the imagingquality.The spectral range of the final design of the system working in3-5μm, workingparameters are as follows: the F number is4, the effective focal length is400mm, thefield of view of4.58degrees. The entire wavelength range without vignetting in thefull field of view. Simulation results show that the imaging quality of pre imagingsystem is close to the diffraction limit, the Encyclopedia of field RMS spot diameter is5.9μm. The simulation results show that this design method can be used for thedesign of large aperture spatio-temporal modulated Fourier transform imagingspectrometer pre imaging system.