Abstract

The fluorescence from living bacteria, induced by a ultrashort 270 nm pump-pulse is depleted up to 50 percent by an optically delayed ultrafast 800 nm probe-pulse in a pump-probe arrangement. Depletion is also observed for Trp in water in contrast with organic molecules such as Naphtalene or diesel fuel, despite similar absorption and fluorescence spectra. This remarkable difference allows us to propose a new remote sensing method able to efficiently discriminate organic from biological aerosols.

© 2005 Optical Society of America