Abstract: A digital frequency domain fluorometer utilizing a computer-controlled digital data acquisition system is use for the study of fluorescence and phosphorescence phenomena in the bio-chemical, biological and bio-physics arts. The computer is used for the direct collection of data, as well as for the filtering and calculation of the phase and modulation values of the sample under study. From these values, fluorescence lifetimes and anisotropy decay times can determined. The digital data acquisition system provides for the simultaneous collection and processing of several modulation frequencies. In addition, the digital frequency domain fluorometer can utilize an array detector for detecting the modulated light from the various samples under study. The use of the array detector provides a means for independently collecting data over a large number of pixels. This configuration allows for a time resolved image to be collected at once.