Translator Disclaimer
11 November 2002 GaAs/AlGaAs based multiquantum-well infrared detector arrays for low-background applications
Author Affiliations +
A long-wavelength large format Quantum Well Infrared Photodetector (QWIP) focal plane array has been successfully used in a ground based astronomy experiment. QWIP arrays afford greater flexibility than the usual extrinsically doped semiconductor infrared (IR) arrays. Recently, we operated an infrared camera with a 256x256 QWIP array sensitive at 8.5 μm at the prime focus of the 5-m Hale telescope, obtaining the images. The remarkable noise stability - and low 1/f noise - of QWIP focal plane arrays enable camera to operate by modulating the optical signal with a nod period up to 100 s. A 500 s observation on dark sky renders a flat image with little indication of the low spatial frequency structures associated with imperfect sky substration or detector drifts. At low operating temperatures for low-background irradiance levels, high resistivity of thick barriers in the active region of QWIPs impeded electrons from entering the detector from the opposite electrode. This could lead to a delay in refilling the space-charge buildup, and result in a lower responsitivity at high optical modulation frequencies. In order to overcome this problem we have designed a new detector structure, the blocked intersubband detector (BID) with separate active quantum well region and blocking barrier.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Sarath D. Gunapala, Sumith V. Bandara, James J. Bock, Michael E. Ressler, John K. Liu, Jason M. Mumolo, S. B. Rafol, Michael W. Werner, and David A. Cardimona "GaAs/AlGaAs based multiquantum-well infrared detector arrays for low-background applications", Proc. SPIE 4823, Photonics for Space Environments VIII, (11 November 2002);


Back to Top