J. Phys. Colloques
Volume 48, Number C7, Décembre 19871st International Laser M2P Conference
|Page(s)||C7-471 - C7-473|
J. Phys. Colloques 48 (1987) C7-471-C7-473
SPECTROSCOPIE OF LASER DYE OXAZINE-170 AS A FUNCTION OF ENVIRONMENT AND pHM. EYAL, R. GVISHI and R. REISFELD
Department of Inorganic and Analytical Chemistry, Hebrew University , IL-91904 Jerusalem, Israel
Absorption end emission spectra of Oxazine - 170, which is one of important laser dyes in the region of 600-700 nm were studied as a function of environment in water, ethanol, methanol, tetrahydrofuran, chloroform, in thin films of polymethylmethacrylate (PMMA) and sol-gel thin films, and in bulk sol-gel glass. The absorption spectra are pH sensitive and the pH dependence reveals existence of two distinct species of oxazine, a cationic form and a molecular form, extinction coefficient of the latter being about half of the former. The quantum yield of the cationic form is high while the quantum yield of the molecular form is an order of magnitude lower. Formation of dimers at high concentrations of oxazine poses a serious problem in thin films, which may be remedied by decreasing the concentration of the dye and by multiple thin film coatings. The bulk glasses show quantum efficiency dependent on conditions of preparation. These results form a frame of guidelines for a choice of optimal environment of a laser dye, whether in solutions or in a solid matrix.