Impact of the rotatory property of TeO₂ crystal on its spectral characteristics

TeO2 is the main imaging crystal of acousto-optic tunable filter. There are chromatic aberration and drift in the crystal itself while the spectroscopic imaging. In this paper, based on the fundamental theory, the impact of TeO2 crystal optical activity to dichroism as the acousto-optic tunable filter was researched and its basic parameters were optimized. The I.C.Chang theoretical system and the P.A.Gass modified theoretical system were compared and analyzed. The results show that the two theoretical systems are quite different when the relationship of ultrasonic frequency coordination is calculated results in the infrared. Assuming that it was caused by the ignored the rotatory property of crystal of I.C.Chang theory, the design method of acousto-optic tunable filter based on P.A.Gass theory is applicable to infrared. The influence of rotatory property on the spectroradiometric property was smaller when the incident polar angle less than 30. Through comparative analysis research, incident polar angle of design should be less than 54.7 , which can maintain higher figure of merit of sound and light and a lower level of the ultrasonic frequency; in the infrared, the incident polar angle of the design should be less than 39.2 , between two frequency coordination deviation f is smaller.