Development of multi-spectral QWIPs for extrasolar planets imaging

One of the most promising approaches for direct imaging of extrasolar planets is based on the next generation of extremely large ground-based telescopes and original differential observing techniques to overcome atmospheric fluctuations problems. One possibility is the use of phase-mask coronagraphy coupled with spectral differential imaging. Multispectral Quantum Well Infrared Photodetectors (QWIPs) are a promising technological solution that could answer the stringent requirements of this challenging topic. We present here the scientific background, the technical requirements as well as the possible technical approaches that are explored in the frame of a project funded by the ANR (Agence Nationale de la Recherche). In particular, we will describe the strategy retained for the design of the QWIP active layer.