Broadband and Dual Color High Speed MCT MWIR Modules

摘要

For 3rd Gen applications, AIM is presently launching its new high speed mercury cadmium telluride (MCT) modules. Two configurations are developed: a 256x256 40μm pitch device in a broadband 3.4-5μm design and a 192x192 56μm pitch device in a dual color mid wave (MWIR) design. The dual color device provides spectral selection with temporal and spatial coincidence for both colors using a new AIM proprietary technology. The spectral bands presently selected are 3.4-4 and 4.2-5μm. In any case, a very high frame rate of 800Hz full frame rate for the broadband and 870Hz for the dual color design are realized. The frame rate is equivalent to a data rate of 80MHz pixel rate. Arbitrary subframes in a step size of 8 pixels can be read out at higher frame rates just limited by the 80MHz pixel rate. The focal plane arrays are integrated in AIM standard dewars with either 1Watt, 1.5Watt or 2Watt split linear coolers to accomplish for various cooldown requirements. The command and control electronics is miniaturized and folds around the dewar for minimum volume and good electromagnetic interference (EMI) and vibration/shock immunity. Each of the 8 analog outputs running at 10MHz has an individual 14 Bit analog to digital converter (ADC). The digital data stream is multiplexed on just 2 high speed serial lines using parallel to serial converters. This allows undisturbed transfer of high resolution data over distances as long as 30m, an optical link, available as an option, provides even wider separation. This feature allows simplified integration in slip ring systems on platforms etc. All DC voltages are derived on board from just 1 5V supply for improved ground loop immunity. A fast digital signal processor (DSP) based image processing board is available for non uniformity correction, visualization and some extra image analysis applications like calculating ratios of colors etc. The present status of the 2 new modules is presented together with measured data. Results of tests with a sequential multi color MCT camera are shown to demonstrate the capabilities of spectral selective detection. An outlook is given on new activities at AIM on dual band QWIP devices.