A system for detecting weak light signals with nanosecond resolution

A simple method for detecting time-resolved weak light signals with a digital oscilloscope, which allows detection of several photons per one excitation period, is described. A system for detecting low-temperature photoluminescence with a resolution of 15 ns has been implemented on the basis of this technique and a method for attaining a resolution of 1–3 ns has been developed. The luminescence kinetics of Si/GexSi1 − x/Si quantum wells was measured in the near-IR region.