First demonstration of megapixel dual-band QWIP focal plane array

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 mid-wave infrared (MWIR) band extends from 4.4 – 5.1 µm and FWHM of the long-wave infrared (LWIR) band extends from 7.8 – 8.8 µm. Dual-band QWIP detector arrays were hybridized with direct injection 30 µm 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 68K operating temperature. The preliminary data taken from the first megapixel QWIP FPA has shown system NEΔT of 27 and 40 mK for MWIR and LWIR bands respectively.