Laser-induced dye fluorescence in a drop

摘要

Fluorescence of solutions of rhodamine 6G in the form of single drops of millimeter sizes excited by the intense IR and visible laser radiation (with duration of laser pulses of approximately 10 ns and wavelengths of 1064 and 532 nm) is experimentally investigated. It is found that the power thresholds of fluorescence excitation for drops comprising the dissolved dye are by an order of magnitude less than for a cell with dissolved dye. The dichromatic drop fluorescence has been revealed, which is manifested through the occurrence of two maxima in the fluorescence spectrum of drops comprising dissolved rhodamine 6G. The first maximum coincides with that of the dye fluorescence spectrum, while the second maximum is shifted by approximately 1000 cm$+$MIN@1$/ and is on the slope of the fluorescence line profile. It is shown that the duration of drop fluorescence does not exceed the duration of the exciting pulse.