Free-running InGaAs/InP Avalanche Photodiode with Active Quenching for   Single Photon Counting at Telecom Wavelengths
  We present an InGaAs/InP avalanche photodiode with an active quenching circuit on an ASIC (application specific integrated circuit) that is capable of operating in both gated and free-running modes. The 1.6mm2 ASIC chip is fabricated using CMOS (complementary metal oxide semiconductor) technology guaranteeing long-term stability, reliability and compactness. In the free-running mode we find a single photon detection efficiency of 10% with <2kHz of noise. 
R. T. Thew, D. Stucki, J-D. Gautier, A. Rochas, and H. Zbinden