Water soluble blue-green lasing dyes for flashlamp-pumped dye lasers

2-(4-Pyridyl)-5-phenyloxazole (4PyPO) and its pyridinium salts have been investigated for laser action in the violet and blue-green spectral regions, respectively. The phenyloxazolyl pyridinium salts show good lasing characteristics, broad tuning ranges, and superior photochemical stability when compared with coumarin 175 in water. Recommendations were made on how the lasing maxima could be blue or red shifted and how the output power and photochemical stability of the new classes of laser dyes could be made to approach that of C8F, which is one of the most photochemically stable lasing dyes reported to date. Because of the reactivity of the nonbonding electrons on the pyridyl group of 4PyPO, hundreds of new laser dyes are possible from the parent dye. A new generation of water soluble, low threshold multifluorophoric laser dyes capable of intramolecular energy transfer and intramolecular triplet state quenching was proposed.