|
According to the common understanding, the 3rd generation of infrared (IR) detection modules is expected to provide advanced functionalities like more pixels, multicolor or multiband capability, higher frame rates and better thermal resolution. This paper is intended to present the present status at AIM on such technologies. A high speed device with 256 X 256 pixels in a 40μm pitch is designed to provide up to 800 Hz full frame rate with pixel rates as high as 80 Mpixels/s. The read out circuit is designed to stare while scan in a flash integration mode to allow nearly full frame integration for even 800 Hz frame rate. A miniaturized command and control electronics with 14 Bit deep digital output and a non uniformity correction board capable to take into account non linear self learning scene based correction models are developed together with the integrated detector cooler assembly (IDCA). As working horse for dual color/band capabilities, AIM has developed a sequential multi color module to provide customers with a flexible tool to analyze the pros and cons of spectral selective detection. The module is based on a 384x288 mercury cadmium telluride (MCT) detector available in the mid wave (MWIR) or long wave spectral band (LWIR). A rotating wheel with 4 facets for filters or microscanner plates provides spectral selectivity. AIM's programmable MVIP image processing is used for controlling the detector and for non uniformity correction. The MVIP allows set the integration time and NUC coefficients individually for each filter position for comparable performance to accurately evaluate the pay off of spectral selectivity in the IR. In parallel, a dual color detector FPA is under development. The FPA is realized as a MCT MWIR device, LWIR, however, is also doable. Dual color macro cells are realized with 192x192 pixels in a pitch of effectively 56 μm. The cell design provides, that both colors detect radiation from target points identical within the limited resolution of the optics to ensure coincident detection plus compensates the significant variation in photon flux of the different colors to output the analog signal at approximately the same level for good thermal resolution and correctability. The photovoltaic device is realized using AIM's mature liquid phase epitaxy. Since quantum well (QWIP) technology has proven state of the art results based on a well established material system, AIM is heading for QWIP devices for most affordable solutions in the MWIR/LWIR dual band applications. A summary of state of the art results achieved so far as basis for a QWIP dual band detector is presented.
|
