Widely tunable pulsed UV source for laser-induced fluorescence of bioaerosols

Fluorescence induced by ultraviolet laser light has shown a strong potential to help detect and identify hazardous bioaerosols. After several demonstrations limited to standard 266 nm or 355 nm sources, recent developments emphasized the advantages of tunable excitation or time-resolved experiments to increase discrimination capabilities. Taking advantage of the recent availability of frequency converting crystals with unprecedented efficiency, we present a three-stage laser design suited to the generation of 500 picoseconds pulses of several microjoules ruggedly tunable from 290 to 350 nm.