Photochemical products in coumarin laser dyes

Abstract
The photochemical degradation processes occurring in a flashlamp‐pumped dye laser using an ethanol solution of 7‐diethylamino‐4‐methylcoumarin have been investigated in detail. The pump radiation gives rise to two irreversible reaction paths, resulting in a total of five photochemical products. One of these substances inhibits laser action because of its optical absorptivity at laser wavelengths. Suggestions for extending dye lifetimes based on this investigation are given.