Curved large-format infrared focal plane arrays

High resolution, wide field-of-view, infrared (IR) imagers find use in defense and commercial applications. Achieving consistent sensitivity and illumination across the field of view, with a compact optical design, is achievable by curving the focal plane array (FPA). We demonstrate the ability to the spherically curve initially flat mid-wave IR (MWIR) sensors by implementing post-processing modifications. We first develop the methodology using silicon die as mechanical surrogates. We then applied it to hybridized arrays, utilizing 4k x 4k, 10 um pixel pitch, MWIR III-V compound semiconductor photodetectors. Hybridized fanout chips were used to evaluate the bandgap and dark current uniformity after curving the arrays, and fully imaging FPA assessed the operability of curved arrays. This result is the first ever demonstration of a spherically-curved, cryogenically-cooled MWIR FPA.