We are particularly interested to develop label-free techniques to study tissue autofluorescence and other optical signatures for biomedical research and clinical diagnosis.  To this end we have developed portable instrumentation that provides ultrashort pulsed laser excitation in the u.v. and blue spectral regions and analyses the resulting autofluorescence with respect to wavelength and lifetime - typically  using time-correlated single photon counting (TCSPC).  Because all the detected photons are combined into a single point measurement, we can detect sufficient photons in a few seconds to permit time-resolved analysis of complex decay profiles in one or more spectral channels.