New applications such as high-data-rate, photon-starved, free-space optical communications require photon counting at flux rates into gigaphoton-per-second regimes coupled with sub-nanosecond timing accuracy. Current single-photon detectors that are capable of handling such operating conditions are...

This non-destructive, optical fatigue detection and monitoring system relies on a small and unobtrusive light-scattering sensor that is installed on a component at the beginning of its life in order to periodically scan the component in situ. The method involves using a laser beam to scan the surface of...