Time correlation method for measuring fluorescence decays with a cw laser

Abstract
A simple experimental approach to measuring fluorescence decay by time correlation signal analysis is described. The approach allows the use of continuous wave excitation and inexpensive detection‐signal processing apparatus. The technique is demonstrated using a cw He–Cd laser. The transient response of the instrument is 0.88 ns, limited by the photomultipliers. The fluorescence lifetime of rose bengal in ethanol is determined, in absence of reorientation relaxation, to be 0.66±0.04 ns.