A system for time-resolved laser fluorescence spectroscopy with multiple picosecond gating

A computer‐controlled system for time‐resolved fluorescence spectroscopy is described. The system provides the simultaneous acquisition of the fluorescence decay curve, of the time‐integrated emission spectrum, and of two time‐gated spectra. Gating within the fluorescence decay is provided by setting up windows in the output of the time‐to‐amplitude converter in single photon timing instrumentation. The gate parameters (position and width) are fully programmable. Depending on the laser source used, time resolutions between 45 and 150 ps are obtained. Therefore, in most situations no deconvolution procedures are required to elaborate the spectra. The system has been characterized with the aid of suitable test solutions. The results indicate that a correct choice of the gate parameters allows complementary information (in terms of both decay times and emission spectra) of the fluorescence parameters of molecular species in molecular systems.