Life science applications utilize advanced techniques to study biological processes and states. Two prominent techniques are microscopy and flow cytometry. Within microscopy, confocal microscopes are the most advanced instruments providing excellent spatial resolution and high contrast when observing molecules, proteins and cells. Flow cytometers analyze multiple properties of cells rapidly flowing through a fluidic system. Both techniques usually color cell structures with bright fluorescent dyes to label specific structures of interest or to increase the contrast.

These techniques are sensitive to sample damage due to overillumination. Thus, a high-sensitivity detector like a single-photon avalanche diode (SPAD) is needed. These techniques also require a high speed system due to scanning (in confocal microscopy) or the rapid flow (in flow cytometry). FLIM, additionally, requires precise picosecond timing precision.