利用串联双滤波技术改善声光滤波器光谱分辨率的实验研究

Experimental research on improving the spectral resolution of an acousto-optical tunable filter by series double-filtering technique

考虑旋光性设计制作了两个非共线型声光可调滤波器(AOTF),通过前后放置对信号光进行两次的级联滤波。调节前后两个AOTF所加的超声频率值,保证前后两个AOTF存在透射光谱的叠加区,从而实现光谱分辨率的提升及调控。实验结果表明,双滤波技术还可以有效抑制AOTF透射光谱的旁瓣效应,改善透射光谱的纯度。

A tellurium dioxide（TeO2）non-collinear acousto-optic tunable filter（AOTF）is a new kind of light splitting device based on abnormal acousto-optic interaction.Spectral resolution is one of the key parameters in the design and applications of an AOTF.In this paper,using the AOTFs designed considering the rotatory property of the TeO2 crystal,we experimentally investigate the double-filtering performance of the two AOTFs arranged in tandem.Adjusting the frequency of the radio frequency source,we can control and enhance the spectral resolution of the filtering system.In the experiment,a 25%enhancement of the spectral resolution has been acquired.Also,it is demonstrated that the double-filtering technique can suppress the sidelobe of the diffracted light beam.So the double-filtering technique is a good method in enhancing the filtering performance of an AOTF.And this technique will promote the applications of an AOTF in hyperspectral imaging and other related fields.