Simplified QWIPs for low-temperature and low-background applications

Abstract

Quantum well infrared photodetector (QWIP) technology has developed rapidly in the past decade culminating in the demonstration of large format focal plane arrays. Most of the efforts so far have been on tactical applications in which an increased operating temperature is the major objective. For strategic applications with a cold background and a faint target, low temperature operation is required. Under these conditions, improving the conversion efficiency (quantum efficiency times gain) is very important for QWIPs to collect sufficient signal. Simplified QWIP (S-QWIP) structures with increased optical gains have been demonstrated. In this presentation, experimental results of several S-QWIPs will be given. The properties of simplified QWIPs will be examined at low temperatures with a low background and a faint target. Results of a computer simulation with an unresolved target will be discussed.