LHC BEAM INSTRUMENTATION FORUM<BR>Single-Photon Detection at Telecommunication Wavelengths: Performance and Applications to Classical and Quantum Comm

by Gregoire Ribordy (UNIVERSITÉ)

Tuesday 5 Jun 2001, 16:00 → 17:00 Europe/Zurich

866/2-D05 (CERN)

Single-photon detection is useful in a variety of fields either to reach the ultimate sensitivity limit in optical measurements or to study and exploit the quantum nature of light. In this presentation, we focus on single-photon detection at telecommunication wavelength (between 1.3 mm and 1.55 mm). These wavelengths correspond to a high transparency window in optical fibers. However, in this region of the spectrum the detection efficiency of photomultipliers is extremely low. Instead, Germanium or InGaAs/InP avalanche photodiodes polarized above breakdown voltage can be used. In this mode, a single carrier within the diode, generated for example by the absorption of a photon, triggers a macroscopic electron avalanche. We will present typical experimental set-ups and look at recent results obtained with InGaAs/InP avalanche photodiodes.