SOLID-STATE SINGLE-PHOTON DETECTORS

This paper reviews the state of the art of some new photon-counting de tectors. We measured the performance of various commercial silicon, ge rmanium, and InGaAs/lnP single-photon avalanche diodes (SPADs) in the 0.8- to 1.55-mu m wavelength range. Optimized silicon devices reach 70 % quantum efficiency at 800 nm and can work up to 1.1 mu m. However, g ermanium and InGaAs SPADs are sensitive up to 1.4 and 1.6 mu m, respec tively, with a few percent quantum efficiency. In all samples we measu red noise equivalent powers less than 10(-15) W/Hz(1/2). Compared with vacuum tubes, SPADs have different advantages such as reliability, ro ughness, low voltage and simple electronic requirements. Furthermore, it is easy to arrange them in the form of arrays, which are required i n astronomy and luminescence measurements. Moreover we investigated th e performance of a SPAD germanium quad sensor. By using proper driving electronics we avoided optical cross-talk between pixels and we prese nt here the preliminary results of our experiments. (C) 1996 Society o f Photo-Optical Instrumentation Engineers.