Picosecond Fluorescence Spectroscopy By Time-Correlated Single-Photon Counting

Abstract
We describe the recent progress made in our laboratory on the time-resolved fluorescence spectroscopy by the combination of stable short-duration pulses from a CW mode-locked laser and a time-correlated single-photon counting method. Particular emphasis is placed on the achievement of high time resolution with side-on and microchannel-plate photomultipliers. We also discuss the limitation of using this method in the picosecond time range. Several applications of this spectroscopy such as the measurements of fluorescence decay characteristics and time behavior of fluorescence depolarization are reported. It is also shown that the high sensitivity of this method with pico-second time resolution is very suitable for the temporal rejection of cumbersome background-fluorescence in Raman spectroscopy. Finally, we present a novel method of photon time-of-flight fluorescence spectroscopy, in which an optical fiber is employed as a dispersive element.