HgCdTe-based APD focal plane array for 2D and 3D active imaging: first results on a 320 x 256 with 30 µm pitch demonstrator

Abstract

CEA-Leti has developed a new 320x256 hybrid focal plane array (FPA) for flash LADAR imaging. The detector array consists of 30μm pixel pitch MWIR HgCdTe avalanche photodiodes operating at 80K and the readout integrated circuit (ROIC) is fabricated on a standard 0.18μm CMOS process. The custom ROIC can operate as a passive thermal imager or a flash LADAR imager. In this second mode, each pixel will provide the time of flight measurement (3D) and the returned intensity (2D) of one laser pulse. For the first laboratory trials the e-APD photodiode array performances were measured in passive mode and the same FPA was then tested in one shot LADAR mode. This paper describes the readout IC pixel architecture and reports the first electro-optical test results in both passive and active modes. This new prototype takes advantage of the latest developments of the partnership between Sofradir and CEA-Leti.