Detection of nondelayed photons in the forward-scattering of picosecond pulses

摘要

We perform time-correlated single-photon counting measurements on 9 ps pulses from a cw mode-locked Nd laser passed through highly turbid water suspensions of Intralipid~(TM), which is a phantom medium widely used for light propagation studies. By detecting photons emerging at very small angles with a system whose pulse-response duration is ～34 ps full width at half-maximum, we obtain time-of-flight distributions in which the contributions of photons nondelayed by scattering events are evident up to very high values of Intralipid concentrations.