Development of MWIR T2SL photodetectors at ASELSAN Inc.

Abstract

ASELSAN, the largest defense company in Turkey, develops high performance electro-optical systems for various applications. Due to the technical challenges and relatively higher cost associated with MCT technology, there is a search for an alternative material system all over the world, especially for the applications that need relatively low quantum efficiency and high volume production. Research and development activities have been carried out on developing InAs/GaSb T2SL detectors for mid-wavelength infrared (MWIR) technology in ASELSAN. In this paper, recent results for 15μm pitch MWIR T2SL and 10μm pitch MWIR T2SL detectors are presented. InAs/GaSb T2SL epilayers are used for FPA fabrication with mesa pixel structures. Typically, over 99% operability and less than 25 mK NETD values are achieved for 15 μm pitch 640x512 format MWIR T2SL FPAs at IDDCA level (F/4). Besides ongoing efforts on development of FPAs with 15 μm pixel pitch, development activities for pixel pitch reduction are also initiated recently for MWIR T2SL FPAs for improving resolution and promising results are achieved. For this purpose, MWIR T2SL FPAs with 1280x1024/10μm resolution/pixel pitch are fabricated and NETD values less than 25 mK (F/2) with pixel operability of 97% are achieved for the first prototypes.