Fluorescence lifetime determination for application in microscopy

A recent development in fluorescence microscopy is the fluorescence lifetime imaging microscopy. In this type of microscopy the lifetime of the excited state of the fluorescent molecules is of interest rather than the amount of light emitted. By evaluating the response (emission light) of the system (fluorescent molecules) to a specific input signal (excitation light) the fluorescent lifetime can be determined. Different input signals are possible including light pulses, the sinusoidally modulated light and the white-noise modulated light. In this paper we describe two systems under development in our laboratory based on the latter two input signals.