Supercontinuum source tuned by an on-axis monochromator for fluorescence lifetime imaging.

We report on the application of an optically tunable coherent white light source, based on the supercontinuum generation from microstructured optical fibres, to fluorescence lifetime imaging (FLIM) microscopy and Foerster resonance energy transfer (FRET). A prototype lens based on monotonic longitudinal chromatic aberration is used for tuning the supercontinuum wavelengths from 400 to 1000 nm and acts as an axial monochromator, suitable for fibre delivery in confocal microscopy.