High resolution time-domain fluorescence lifetime imaging for biomedical applications

We report the development of a whole-field fluorescence lifetime imaging (FLIM) system with high temporal resolution based on a time-gated image intensifier. The optimized temporal gate width is <100ps, and changes in the environment of a fluorescent phantom, causing lifetime differences less than 10ps, have been imaged. The versatility of this FLIM system has been demonstrated by measuring both the temporal and spectral profiles of multiple fluorescent samples in a single acquisition. Initial fluorescence lifetime images suggest that this technique can provide a means of distinguishing between different tissue constituents.