Single-photon imaging in infrared will add a new valuable tool to night imaging cameras. Despite years of development, high-sensitivity SWIR cameras are still expensive and not ready for large-volume production. Germanium (Ge) is a promising semiconductor to convert SWIR radiation and it has seen extensive development in conjunction with highspeed optical communications. We are demonstrating a new low-light level infrared array technology based on the single-photon sensitive Geiger avalanche PhotoDiode (Si-GPD) array technology developed at aPeak and low-dislocation Germanium processing developed at MIT. The core of the imaging camera is a Ge:Si photon-counting GPD pixel with CMOS readout. The primary technology objective is to demonstrate through prototyping and semiconductor process development the technical feasibility of single-photon detection cameras sensitive in the SWIR and set the performance specifications. We report on prototype Ge:Si structures compatible with the GPD operation and technology. We demonstrate >80% quantum efficiency at 1310nm and 45%-60% quantum efficiency at 1550nm. Dark current measurements indicate that single-photon sensitivity (2.6x10-18W/pixel) is achievable by cooling the detector at cryogenic temperatures down to 53K. A digital developed to provide adjustable dynamic range and frame rate is reported. Because the GPD detectors have intrinsic excellent gating and ranging capability, the pixel architecture is developed to enable the dual mode operation - passive illumination two-dimensional imaging (night vision) and active illumination three-dimensional imaging.

Date Published: 3 May 2010
PDF: 9 pages
Proc. SPIE 7660, Infrared Technology and Applications XXXVI, 76603E (3 May 2010);

Published in SPIE Proceedings Vol. 7660:
Infrared Technology and Applications XXXVI
Bjørn F. Andresen; Gabor F. Fulop; Paul R. Norton, Editor(s)