QWIP products and building blocks for high-performance systems

Abstract
Standard GaAs/AlGaAs Quantum Well Infrared Photodetectors (QWIP) are coming out from the laboratory. In this presentation we demonstrate that production and research cannot be dissociated in order to make the new generation of thermal imagers benefit as fast as possible from the building blocks developed by researchers. Since 2002, the THALES Group has been manufacturing sensitive arrays using QWIP technology based on AsGa techniques through THALES Research and Technology Laboratory. This QWIP technology, integrated in IDDCA built by Sofradir, allows the realization of large staring arrays for Thermal Imagers (TI) working in the IR band III (8-12 μm). A review of the current QWIP products, offered by Sofradir, is presented. In the past researchers claimed many advantages of QWIPs. Uniformity was one of these and was the key parameter for the production start. Another advantage widely claimed also for QWIPs was the so-called band-gap engineering, allowing the custom design of quantum structure to fulfill the requirements of specific applications like very long wavelength or multispectral detection. In this presentation, we present the performances for Middle Wavelength InfraRed (MWIR) detection and demonstrate the ability of QWIP to cover the two spectral ranges (3-5 μm and 8-20 μm). At last but not least, the versatility of the GaAs processing appeared for QWIPs as an important gift. This assumption was well founded. We give here some results achieved on building blocks for two color QWIP pixels. We also report the expected performances of focal plane arrays we are currently developing with the CEA-LETI-SLIR.