Advantages of T2SL: results from production and new development at IRnova

IRnova has been manufacturing mid wave infrared (MWIR) detectors based on InAs/GaSb type-II superlattices (T2SL) since 2014. Results from the first years of production of MWIR focal plane arrays (FPAs) with 320 x 256 pixels on 30 μm pitch using the ISC9705 readout integrated circuit (ROIC) is presented in terms of operability, temporal and spatial noise equivalent temperature difference (NETD) and other key production parameters. Results on image stability of T2SL detectors show that no deterioration of image quality over time can be observed. Furthermore it is shown that the non-uniformity correction remains stable even after repeated detector temperature cycles. Spatial and temporal NETD for fabricated mid wave arrays show a temporal NETD of 12 mK and a spatial NETD of 4 mK with f/2 optics and 8 ms integration time. When studied over a large scene temperature, the spatial noise is still less than 60 % of the temporal noise. Furthermore, 640 x 512 mid wave FPAs with 15 μm pitch using the ISC0403 ROIC are entering an industrialization phase. Temporal and spatial NETD values of 25 mK and 10 mK, respectively, are obtained with f/4 optics and 22 ms integration time and the operability is 99.85 %. A status update on the development of T2SL detectors for short wave, mid wave and long wave infrared wavelength regions for existing and new applications is given and recent development towards higher operating temperature, smaller pitch and larger FPA formats is presented.