Pulsed interleaved excitation fluorescence spectroscopy with a supercontinuum source

Abstract

Pulsed Interleaved Excitation (PIE) improves fluorescence cross-correlation spectroscopy (FCCS) and single pair Förster Resonance Energy Transfer (spFRET) measurements, by correlating each detected photon to the excitation source that generated it. It relies on the interleaving of two picosecond laser sources and time correlated single photon counting (TCSPC) detection. Here, we present an optical configuration based on a commercial supercontinuum laser, which generates multicoulour interleaved picosecond pulses with arbitrary spacing and wavelengths within the visible spectrum. This simple, yet robust configuration can be used as a versatile source for PIE experiments, as an alternative to an array of picosecond lasers and drivers.