A highly ruggedized infra-red sensor module has been developed which is suitable for a variety of fast framing
applications in hostile fire detection and in scientific or industrial metrology. The sensor offers <1000fps in the full
384x384 format and useful images up to 6500fps in smaller formats. High operability for either mid-wave or long-wave
IR applications is assured with high performance MOVPE fabrication technology. The paper reports design concepts
and performance data for the MW variant.
Detector arrays using Metal-Organic Vapour Phase Epitaxy (MOVPE) grown HgCdTe (MCT) on GaAs substrates have been in production at SELEX Galileo for over 10 years and are a mature technology for medium wave, long wave, and dual-band tactical applications. The mesa structure used in these arrays is optimised for MTF, quantum efficiency and dark currents. Further development of the technique has migrated to very long wave and short wave bands, mainly for space and astronomy applications, and for mid wave applications towards smaller pixels and higher operating temperatures. The emphasis of this paper is on recent experiments aimed at further improving HOT performance.
Raising the operating temperature of infrared detectors has benefits in terms of reduced cooler power and increased life
and enables an overall reduction in size and weight for handheld applications. With MCT the composition can be tuned
to achieve the required wavelength range at a given temperature. Work on detectors operating in the 3-5μm atmospheric
transmission window at operating temperatures up to 210K will be described. The influence of limiting factors such as
excess noise, radiation shield emission, dark current and injection efficiency will be presented.
Packaging aspects will be discussed emphasizing the importance of achieving low cost, weight and power for handheld
applications. The impact of the detector design on overall system size and performance is considered with specific
attention to time to image, passband and f-number.
Finally images will be presented showing performance from a high operating temperature (HOT) camera.