Demonstration of Megapixel Dual-Band QWIP Focal Plane Array

Abstract

Quantum well infrared photodetectors (QWIPs) are well known for their stability, high pixel-pixel uniformity and high pixel operability which are quintessential parameters for large area imaging arrays. In this paper we report the first demonstration of the megapixel-simultaneously-readable and pixel-co-registered dual-band QWIP focal plane array (FPA). The dual-band QWIP device was developed by stacking two multi-quantum-well stacks tuned to absorb two different infrared wavelengths. The full width at half maximum (FWHM) of the midwave infrared (MWIR) band extends from 4.4-5.1 ¿m and FWHM of the long-wave infrared (LWIR) band extends from 7.8-8.8 ¿m. Dual-band QWIP detector arrays were hybridized with direct injection 30 ¿m pixel pitch megapixel dual-band simultaneously readable CMOS read out integrated circuits using the indium bump hybridization technique. The initial dual-band megapixel QWIP FPAs were cooled to 68 K operating temperature. The preliminary data taken from the first megapixel QWIP FPA has shown system NE¿T of 27 and 40 mK for MWIR and LWIR bands, respectively.