Photophysical and lasing properties of a new ester derivative of rhodamine 6G

Absorption and fluorescence spectra, fluorescence decay curves and laser emission characteristics of a newly synthesized dye belonging to the rhodamine family, dissolved in several aliphatic monoalcohols and in water/ethanol mixtures, have been obtained. The new dye incorporates the chromophoric group of rhodamine 6G, but with the ethyl substituent in the ester group of this molecule replaced by the p-ethoxycarbonylbenzyl group, and can be considered as a molecular model for a previously described rhodamine dye with a polymerizable double bond that has demonstrated to lase efficiently with good photostability in solid polymeric matrices. The results obtained indicate that the modifications in the dye molecule scarcely affect the photophysics of the rhodamine chromophore. The new rhodamine dye has lasing properties that correlate well with its photophysical characteristics. Laser emission in water solution with efficiencies as high as 10.5% has been obtained.