An electronically tunable ultrafast laser source applied to fluorescence imaging and microscopy including fluorescence lifetime imaging

Abstract

We demonstrate a continuously electronically tunable (435-1150 nm) ultrafast source for fluorescence imaging applications that is derived from a visible supercontinuum generated by injecting infrared femtosecond pulses in to a microstructured fibre. We demonstrate this source applied to confocal and wide-field microscopy, as well as multiwell-plate imaging. We also report first application of a tunable supercontinuum source (TSS) to FLIM and to in situ measurements of relative excitation spectra. We are currently applying this source to hyperspectral imaging and working towards a system for acquiring the full fluorescence excitation-emission matrix. Fluorescence lifetime imaging (FLIM) can provide further information about fluorescent samples and requires a rapidly modulated or pulsed light source, in general, (tunable) ultrafast light sources, particularly in the visible, are complex and expensive and usually require a significant degree of adjustment to achieve tunability