Single-Photon Counters Get a Second Wind
Standard PIN and linear-mode avalanche photodiodes are the devices of choice for most light-detection applications. However, at ultralow-light levels, these detectors fall short because the noise of the readout electronics becomes greater than the photodiode signal. In a wide range of research and commercial applications — such as fluorescence and luminescence detection, DNA sequencing, fluorescence correlation spectroscopy, decay time measurements, flow cytometry, noncontact profilometry,...
Photonics Spectra, March 2005