LWIR/MWIR adaptive focal plane array

Abstract

An Adaptive Focal Plane Array (AFPA) device that enables a chip scale imaging spectrometer is being developed. The AFPA device consists of an array of MEMS tunable filters that is intimately coupled to a dual band IR FPA. The MEMS filters provide narrowband tuning in the LWIR and simultaneous broadband imaging in the MWIR. Each filter element can be independently tuned. In the current design, each filter tunes the wavelength of pixel subarrays. Ultimately, filter size will be reduced to achieve independent wavelength tunability for each pixel element. This unique architecture of an AFPA device enables adaptive spectral analysis of the scene. Rather than collecting the complete hyperspectral cube, methods being developed will enable selection of spatially optimized spectral band sets for a variety of targets and materials that are selected on-the-fly to maximize the contrast between the local background and the target or material to be identified. The analyzed LWIR spectral information may then be overlaid with a pixel registered high resolution MWIR image.