Publications

Germanium exhibits high sensitivity to short-wave infrared (SWIR) and X-ray radiation, making it an interesting candidate for imaging applications in these bands. Recent advances in germanium processing allow for high-quality charge-coupled devices (CCDs) to be realized in this material. In this article, we discuss our evaluation of germanium as an...

We demonstrate a 256 x 256 passive photon counting imager based on hybridization of back-illuminated silicon Geiger-mode avalanche photodiodes to an all-digital CMOS counting chip. Photon detection efficiencies in the 10%-20% are observed at visible wavelengths. The detection efficiency is currently limited by optical crosstalk that leads to elevation of...

We report an array of Shack-Hartmann wavefront sensors using high-fill-factor Geiger-mode avalanche detector quad cells hybridized to all-digital CMOS counting circuits. The absence of readout noise facilitates fast wavefront sensing at low light levels.

We have developed focal-plane arrays and laser-radar (ladar) imaging systems based on Geiger-mode avalanche photodiodes (APDs) integrated with high-speed all-digital CMOS timing circuits. A Geiger-mode APD produces a digital pulse upon detection of a single photon. This pulse is used to stop a fast digital counter in the pixel circuit...

We discuss the properties of Geiger-mode avalanche photodiodes (APDs) and their use in developing an imaging laser radar (ladar). This type of photodetector gives a fast electrical pulse in response to the detection of even a single photon, allowing for sub-nsec-precision photon-flight-time measurement. We present ongoing work at Lincoln Laboratory...