Short-Wave Infrared (SWIR) Pixelated Micro-Polarizer Camera

This proposal is to develop a snap-shot polarimetric camera that operates in the short wave infrared 0.8-2.5um (SWIR). The camera will provide high frame-rate polarimetric data in a compact and lightweight module that will enable deployment in mobile and airborne platforms. Polarimetric enhanced image data has been shown to be highly beneficial for both defense and commercial applications including: target discrimination, mine detection, and remote material identification; however, compact, solid-state solutions do not currently exist in the SWIR owing to the difficulty of fabricating such a device. Our approach is to modify our existing process for fabricating visible sensors utilizing direct bonding of micro-polarizer arrays (MPA)s to a focal plane array (FPA), in order to work with an InGaAs FPA. Previous attempts at this by others found severe crosstalk and poor robustness. 4D plans to address these issues by working with FPA manufacturers to obtain suitable back-thinned FPAs, utilize our proprietary MPA precision alignment system, and knowledge of advanced packaging/bonding methods. The Phase I effort will validate the polarimetric performance between the MPA and FPA. The Phase II effort will fully develop the MPA bonding process to withstand the temperature extremes of airborne platforms and deliver a SWIR micro-polarizer camera.