Expansion of the spectral tuning range of laser radiation from aminocoumarins as a result of acid–base interaction

An investigation was made of the influence of the acid–base interaction on the lasing characteristics of aminocoumarins. As a result of this interaction, complexes with hydrogen bonds and protonated ions are formed and these emit laser radiation at longer wavelengths compared with that emitted by the initial forms of the dyes. The occurrence of two-band lasing (initial form and complex) in a system comprising coumarin 1 and water in dioxane, when the fluorescence spectrum only contains one band, is attributed to the fact that a hydrogen-bonded complex is formed as a result of a fast reaction in the excited state. The tuning range of laser radiation from the coumarins 1 and C6H can be increased appreciably as a result of simultaneous lasing in different forms of the dye.