Properties of silicon photon counting detectors and silicon photomultipliers

Geiger-mode avalanche photodiodes (APD) or photon counting detectors (PCD) have become the basis of a range of new detectors and applications. Such devices are sensitive to single photons and are being adapted to create different detector technologies such as the silicon photomultiplier (SPM). A silicon photomultiplier, so-called because of its similarity in performance to conventional photomultiplier tubes, is based on an array of photon counting detectors but with a single common output. While the silicon photomultiplier does not provide positional information, it does allow photon number resolution and photon counting at higher count rates than are achievable with a solitary PCD. These new detectors are enabling a range of new applications in the fields of medicine, biology, high-energy physics and space exploration. In this paper we report the performance of PCD with dimensions ranging from 20 μm × 20 μm to 200 μm × 200 μm and on 1 mm2 silicon photomultipliers and illustrate the use of an SPM in single photon counting mode.