More and more, hyperspectral images are envisaged to improve the aerial reconnaissance capability of airborne systems, both for civilian and military applications. To confirm the hopes put in this new way of imaging a scene, it is necessary to develop airborne systems allowing the measurement of the spectral signatures of objects of interest in real conditions, with high spectral and spatial resolutions. The purpose of this paper is to present the design and the first in-flight results of the dual-band infrared spectro-imaging system called Sieleters. This system has demonstrated simultaneously a ground sampling distance of 0.5m, associated with a spectral resolution of 11 cm(-1) for the Mid-Wave InfraRed (MWIR) and 5 cm(-1) for the Long-Wave InfraRed (LWIR).

We present a new technique for measuring the modulation transfer function (MTF) of a focal plane array (FPA). The main idea is to project a periodic pattern of thin lines that are canted with respect to the sensor's columns. Practically, one aims the projection by using the self-imaging property of a periodic target. The technique, called the canted periodic target test, has been validated experimentally on a specific infrared FPA, leading to MTF evaluation to as great as five times the Nyquist frequency.

There is an emerging demand for compact infrared instruments, imagers and/or spectrometers, integrated on ground or air vehicles for spatial and spectral data collection. To reach this goal, technological barriers have already been overcome, leading to the development of infrared focal plane arrays (IRFPAs) for high-performance applications (megapixel format, bispectral technology) but also for low-cost and high-volume manufacturing (technology of uncooled micro-bolometers). The next step is to reduce the optics and make it compatible with the successful IRFPAs fabrication technology. This paper presents MULTICAM, a small cryogenic infrared camera. This optical system is composed of multi-level arrays of microlenses integrated in the cryostat and inspired from invertebrate compound eyes. First experimental results will be presented.

Thanks to their wavelength diversity and to their excellent uniformity, Quantum Well Infrared Photodetectors (QWIP) emerge as potential candidates for astronomical or defense applications in the very long wavelength infrared (VLWIR) spectral domain. However, these applications deal with very low backgrounds and are very stringent on dark current requirements. In this paper, we present the full electro-optical characterization of a 15µm QWIP, with emphasis on the dark current measurements. Data exhibit striking features, such as a plateau regime in the I(V) curves at low temperature (4 to 25 K). We show that present theories fail to describe this phenomenon and establish the need for a fully microscopic approach.

Electroluminescence associated with impact excitation or ionization of deep Cr(2+) impurity centers in bulk ZnSe is reported. A broad signal of mid-infrared luminescence between 2 and 3 microm is observed once the biased bulk ZnSe device runs into a nonlinear conduction regime. Optical powers in the nanowatt range have been measured at room temperature. The different mechanisms involved in this intracenter infrared light emission are discussed.