Single Photon Techniques for Precision Measurements of Optical Waveforms from Radiative Decays

The measurement of optical waveforms in order to measure physical parameters (radiative li fetimes etc.) is dealt with. The influence of the detection and measurement system and causes of systematic and randon errors are analyzed. The inherently digital techniques ba sed on single photon (SP) detection are shown to have definite advantages over analog techniques. Two basic SP techniques are considered: SP gated counting (SPGC) and measurement of SP delay distribution (SPDD), which are complementary and cover a time range from subnanosecond to long times (> minutes). The time resolution, the effect of background, the randon fluctuations and other factors which set limits to the available measurement range are considered, and experimental results reported. Extension to very low detected intensity and to the infrared spectral range is ana lyzed and experimentally tested.