Study On Dispersion Parts By Bragg Modulating In Imaging Spectrometer

Imaging spectrometer which based on the mechanism of acousto-optic tunable filter has a unique advantage, and TeO2 crystal is the core area which realized dispersion in acousto-optic tunable. For the need of imaging spectrometer, some basic problems in imaging spectrometer which used the material of TeO2 as the dispersion crystal and based on Bragg modulation have been theoretical researched, simulated and experimental validated.Firstly, the ultrasonic frequency coordination relations of the acoustic-optic tunable filter has been studied amply in this paper. By analysis the ultrasonic frequency coordination relations in I.C.Chang theoretical model and P.A.Gass modified theoretical model, come to the ultrasonic frequency coordination relations effects of the rotatory property of the TeO2 crystal, the ultrasonic frequency coordination relations has been simplify designed by the method of the principle of Kernel function nonlinear mapping. And a new form expression of the ultrasonic frequency coordination relations has been proposed for the first time. In considering the case of the rotatory property of the crystal, added an optical wedge exit face of crystal in order to eliminate the image drift due to dispersion effectively, and the optical wedge is optimized by eliminating the dispersion. The resolution which is one of the most important parameter of the imaging spectrometer has been simulating. Finally, the theory of diffraction angle and spectral resolution is verified by the experiment, and calculate the shift of the image to verify the merits of the spectral images imaging.