HgCdTe APDs detector developments at CEA/Leti for atmospheric lidar and free space optical communications

HgCdTe APD detector modules telecommunication are developed at CEA/Leti for atmospheric LIDAR and free space optical (FSO). The development is driven by the design and manufacture of generic sub-assemblies that can be adapted in each detector module to meet the specific detector requirements of each application. The optimization of such subassemblies is detailed in perspective of the challenges that are set by the specifications for detector modules currently developed for atmospheric LIDAR, in the scope of an R&T CNES project for Airbus and an H2020 project HOLDON, and FSO, in the scope of an ESA project and in collaboration with Mynaric Lasercom GmbH. Two detector modules have recently been delivered to Airbus DS for extensive LIDAR simulation tests. Initial characterization of these modules shows that the input noise, NEP=10-15fW/√Hz (5 photons rms) have been reduced by a factor three compared to previously developed large area detectors although the bandwidth have been increased to 180 MHz in order to respond to the requirements of high spatial depth resolution. The temporal remanence was 10^-4 at 200 ns after the detection of short light impulse, which is compatible with demanding LIDAR applications such as bathymetric profiling.