[17p-A502-1~16] 3.7 Optical measurement, instrumentation, and sensor (formerly 3.8)

△ [17p-A502-6] Sub-Gigahertz Pseudo-Random Excitation for Reduction of
Excitation Dead-Time in Fluorescence Lifetime Measurement

〇Sota Ui¹, Keisuke Seto¹, Takayoshi Kobayashi², Eiji Tokunaga¹ (1.TUS, 2.UEC)

Keywords:Fluorescence Lifetime Imaging Microscopy, Fluorescence microscope

In the conventional fluorescence lifetime measurement, fluorescent molecules are repetitively excited with impulsive pulses, and fluorescence is accumulated to obtain the fluorescence decay curve for the lifetime evaluation. There is idle time waiting for the fluorescence quenching in the repetitive excitation. We have studied a methodology to reduce the idle time employing pseudo-random pulsed excitation. The decay curve is retrieved by correlating the fluorescence signal and the pseudo-random sequence used. The fluorescence photon number and signal-to-noise ratio (S/N) are enhanced by reducing the idle time by increasing the number of excitation pulses in the unit time. In the present study, we perform the pseudo-random modulation of the excitation light in a sub-gigahertz range. We demonstrate practical fluorescence lifetime measurement in a few-nanosecond range with an improved S/N.