High-performance SWIR/MWIR and MWIR/MWIR bispectral MCT detectors by AIM

Current development efforts in IR-module technology show two major trends: Reduction in size, weight and power dissipation of IR-systems and further increase in system performance by introducing 3rd Gen IR-modules. Concerning 3rd Gen IR-modules AIM is developing SWIR/MWIR and MWIR/MWIR bispectral MCT detectors making use of its established and qualified MBE technology based on the growth of MCT multi-layers on GaAs substrates. The advantage of multispectral versus single color IR-sensors is the ability to combine sensitivity of two different IR wavelengths in one detector. This greatly enhances the ability to gather information from a scene, which is a significant additional benefit for IR-systems, for applications such as seeker heads, missile warners or counter measures against laser-guided beam-rider weapons. In particular, the combination of the SWIR/MWIR or MWIR/MWIR spectral bands promote an enhanced target discrimination and identification via increased identification range, achieved by enabling the target acquisition in front of cluttered backgrounds or of targets with low thermal signature. The information of the SWIR spectral range, which detects mainly the reflected part of the spectrum, and the passive IR-detection in the MWIR spectral range, can be favorably combined for the data acquisition and subsequent image data processing in our bispectral approach due to its temporal and spatial coincidence of the scene image. In this paper results will be presented of AIM’s SWIR/MWIR, as well as MWIR/MWIR bispectral MCT detectors with 320x256 pixels and a 30 μm pitch. The detectors demonstrate very low color cross-talk, and an excellent NETD in conjunction with low defect densities.