  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.
