High-performance HgCdTe SWIR detector development at SOFRADIR

Abstract

HgCdTe (MCT) infrared detectors offer the possibility to tune the material cut-off wavelength between 1 μm and 14 μm in order to adapt the detector detection waveband to the application need. At the same time the detector operating temperature can be tuned as well as the cut-off wavelength between 77 K and more than 230 K in order to offer high performance. Within this range of wavelengths, the SWIR sub- band (1 μm to 3 μm) presents a growing interest for military, commercial and space applications such as non destructive test, spectrometry, SWIR hyperspectral instruments for space applications, ... In addition to the interest of the waveband, these detectors present the advantage of a combination of high performance with the use of thermoelectrical cooler (TEC). Thus, in order to answer the market need for this type of application, Sofradir has developed infrared detectors in the SWIR waveband based on an adaptation of its MCT material to the required waveband and using low noise readout circuits adapted to operate with low photonic current. This paper presents Sofradir MCT detectors results in this waveband including possible trade-offs between the detector performances and operating temperature in function of the application. Then, the SWIR detectors developments and production at Sofradir are presented. In particular, a 320x256 SWIR focal plane array packaged with a TEC and its performances are shown and a particular attention will be paid to the development in progress of a large SWIR focal plane array with high performances between 150 K and 180 K for space application. Finally, trends for future developments in SWIR waveband at Sofradir will be presented.