Chemical stabilization of the coumarin 1 dye laser

Abstract

The chemical stabilization of coumarin 1, 7-diethylamino-4-methylcoumarin, in a nitrogen laser pumped dye laser and coumarin 311, 7-dimethylamino-4-methylcoumarin, under cw conditions with sulfur-free radical chain transfer agents, are described. The mechanism for stabilization involves encounter of triplet coumarin and ground state coumarin with subsequent radical formation and radical disproportionation catalyzed by the chain transfer agents. The output of the coumarin 1 dye laser decreased 10% when the dye solution was stabilized with cysteine hydrochloride over a 12-h period. The output of the unstabilized dye laser decreased 50% during a similar period of operation.