不同结构长波红外探测器组件的MTF分析

MTF of infrared detector modules with different structures

红外探测器组件作为目标探测和成像系统的核心器件,其空间分辨能力直接影响着探测系统的成像质量.评估探测器组件空间分辨能力时,常使用调制传递函数(MTF),而不同的探测器组件结构与其MTF直接相关.介绍了一套弥散斑直径为30μm的红外小光点测试系统,采用扫描狭缝法测试不同结构红外探测器组件的MTF.测试结果表明叠层电极结构侧面存在的光响应会导致线扩散函数(LSF)展宽和次峰等现象,从而造成探测器组件MTF下降,同时0.17 mm和0.30 mm两种芯片和滤光片间距对于探测器组件MTF的影响甚微,该结果为红外探测器组件杂光抑制设计提供了参考.

The infrared detector module is the key device of target detection and imaging system. Its spatial resolution directly affects imaging quality of detection system. When evaluating the spatial resolution of detector modules,researchers usually adopt modulation transfer function( MTF),which is influenced by the different structures of the detector modules. The basic principle and configuration of infrared micron-spot test system with an optical dispersion diameter of 30 μm was introduced. MTF of detectors with different structures was measured by scanning slit technique. The results show that the profile of overlap electric region is photosensitive. This is the main factor to widen the line spread functions(LSF),cause the secondary peak,and so on. The MTF is thus deteriorated. Meanwhile,the different distance of chip and filter with 0. 17 mm and 0. 30 mm influences slightly the optical crosstalk of the detector module. These results are used for optimizing design of infrared detector modules for stray light control.