光机械式红外探测器中镜面弯曲对探测灵敏度的影响(英文)

The Influence of Mirror Curvature on OpticalDetection Sensitivity in Optomechanical Uncooled IR Detectors

光学读出式红外成像技术是近年来研究的热点,本文讨论了镜面弯曲对光学检测灵敏度的影响。由双材料微悬臂梁组成的非致冷焦平面阵列通过体刻蚀工艺加工而成,由于残余应力的影响,制成的焦平面阵列将会发生弯曲,应力导致的镜面弯曲将会降低光学探测灵敏度。本文通过傅立叶光学模拟了镜面弯曲对光学探测灵敏度的影响,并通过实验验证了该模型。实验和模拟结果表明,在镜面曲率为0 .1mm-1时,光学探测灵敏度将会降低到理想情况的40 %。最后我们用这个模型评价了通过表面修饰来提高光学性能的效果。

This paper discusses the influence of micromirror curvature on optical sensitivity in optomechanical uncooled infrared （IR） detectors. An uncooled IR Focal Plane Array （FPA） containing bimaterial microcantilever arrays is fabricated using a silicon bulk micromachining technique. The fabricated FPA is curved due to the residual stress caused in the microfabrication process. The stress-induced mirror curvature can degrade the optical detection sensitivity of these optical readout detectors. The influence of the curvature is modeled theoretically by Fourier optics and validated experimentally. The optical detection sensitivity is decreased to 40% of the ideal value when the mirror has a curvature of 0. lmm 1. Finally, this analysis method is used to evaluate the improvement of optical performance of FPA after curvature modification.