Sofradir of Palaiseau near Paris, France – a subsidiary of Safran and Thales that makes cooled infrared (IR) detectors for military, space, scientific and industrial applications – is developing its first very-large-format (2048x2048) 15μm-pixel-pitch infrared detector. The supersize IR detector is designed for future scientific space observation equipment and state-of-the-art Extremely Large Telescopes (ELT) for ground observation aimed at tackling major scientific challenges.
The ALFA 2Kx2K (Astronomy Large Focal Array) 15μm-pitch short-wave infrared detector is intended to provide the highest levels of performance in quantum efficiency (QE), dark current and noise in order to optimize IR observations for astrophysicists.
Sofradir is collaborating with the French research centers CEA-Leti in Grenoble and CEA-IRFU in Paris to develop the ALFA near-infrared detector through a European Space Agency (ESA) initiative. Sofradir plans to deliver a fully characterized low-flux, low-noise ALFA prototype in first-quarter 2019.
“ALFA 2Kx2K will enable OEMs to build new instruments, opening up new opportunities for us in astronomy and other sciences, where every single infrared application needs very low flux and low noise compatibility,” says space activities manager Philippe Chorier.
Large-format infrared detectors (greater than 1024x1024) are highly complex devices that only a handful of manufacturers in the world can produce to space-grade standards, says Sofradir. This new low-flux, low-noise near-infrared (NIR) 2Kx2K detector for space astrophysics is the result of developments that the ESA initiated several years ago under its Near Infrared Large Format Sensor Array (NIRLFA) program (on which Sofradir, CEA-Leti and CEA-IRFU have been working since 2009).
The NIR detector is based on mercury cadmium telluride (HgCdTe) as the absorbing material, and includes a read-out circuit (ROIC) with a source follower per detector (SFD) at the input stage.
Sofradir says that the detector’s development will benefit from its experience as a leading manufacturer of IR detectors deployed in space (totaling more than 82 flight models to date). Space programs include: Sentinel 2 and Sentinel 5 (Copernicus), and MTG (Meteosat Third Generation) and Exomars.
“Thanks to ALFA detector, Sofradir will be able to offer a new up-to-date solution for applications in space, science and astronomy,” says Chorier.
Sofradir and its subsidiaries ULIS and Sofradir-EC are exhibiting a selection of top-of-the-line IR detectors and large-format models for airborne, naval, ground vehicle and space applications in Hall 2B G79 at the Paris Air Show (19–25 June).
