Approaches to Single Photon Detection
  We present recent results on our development of single photon detectors, including: gated and free-running InGaAs/InP avalanche photodiodes; hybrid detection systems based on sum-frequency generation and Si APDs; and SSPDs (superconducting single photon detectors), for telecom wavelengths; as well as SiPM (Silicon photomultiplier) detectors operating in the visible regime. 
R. T. Thew, N. Curtz, P. Eraerds, N. Walenta, J-D. Gautier, E. Koller,   J. Zhang, N. Gisin and H. Zbinden