A system and method for measuring fluorescence lifetimes utilizing a light source modulated with a code sequence to interrogate a sample of interest. The system utilizes a low-power continuous-wave laser or light-emitting diode modulated with a digital code sequence to interrogate a sample of interest. A portion of the fluorescence light from the sample is captured with a photo-detector. A correlation of the photo-detector signal and the digital code sequence is calculated to produce an estimate of the time-response of the system.
Light-emitting diode direction indicator