Structure Optimization and Performance Analysis of A Substrate-free Focal Plane Array
无基底焦平面阵列结构优化设计及性能分析

A substrate-free focal plane array (FPA) was proposed and fabricated successfully by authors of this paper based on optical-readout uncooled infrared imaging technique. It has not only simplified the production process, but also improved the infrared imaging quality. However, it is susceptible to mechanical noise (NETDTM) due to the low inherence frequency of monolayer membrane structure, which could lead to the raise of noise equivalent temperature difference (NETD). In order to solve the problem, two kinds of improved structure with strengthened beam were proposed. These two structures were proved to have a significantly increase of inherence frequency (from 74Hz to 835Hz and 404Hz respectively) and reduce NETDTM by two orders of magnitude based on finite element analysis and experimental results by using simplified model and laser displacement sensor, which consequently carry out the structural optimization of FPA.