In this paper we report the use of the dual beam thermal lens technique as a quantitative
method to determine absolute fluorescence quantum efficiency and concentration
quenching of fluorescence emission from rhodamine 6G doped Poly(methyl
methacrylate) (PMMA), prepared with different concentrations of the dye. A
comparison of the present data with that reported in the literature indicates that the
observed variation of fluorescence quantum yield with respect to the dye
concentration follows a similar profile as in the earlier reported observations on
rhodamine 6G in solution. The photodegradation of the dye molecules under cw laser
excitation is also studied using the present method.Cochin University of Science & Technolog
