Ray tracing method for removing sidelobe laser interference in AOTF-based hyperspectral imaging

Abstract

The sidelobe phenomenon of acousto-optic tunable filter (AOTF)-based hyperspectral imaging is the result of the phase mismatching condition, which will reduce the quality of hyperspectral imaging data. This phenomenon can be observed in two specified scenes, namely, high brightness panchromatic target imaging and high brightness monochromatic target imaging. In this paper, the acousto-optic interaction in these two scenes is discussed using the phase matching condition. As a follow-up work of the previous related research, this paper studies laser interference in AOTF imaging, which is a typical example of the second case. A method to remove laser sidelobes in AOTF-based hyperspectral imaging is proposed, which combines a series of procedures including laser point extraction, reverse imaging before AOTF, ray tracing in AOTF, forward imaging process after AOTF, and laser elimination. Experimental results have verified the effectiveness of the proposed method.

Review of acousto-optic spectral systems and applications

“…The double-filtering technique can effectively improve the spectral resolution of the acousto-optic filters. In addition, the primary filtered signal after the AOTF is accompanied by an obvious side flap phenomenon, which comes from the acousto-optic interaction [45][46][47][48]. There is no way to eliminate the side flaps by using the primary filtering technique.…”