Femtosecond laser induced emission enhancement in Rhodamine6G

• We report on the enhancement of fluorescent emission along with quantum yield of Rh6G in Methyl Methacrylate solution upon irradiation with Ti: Sapphire femtosecond laser beam.
• The optimum parameters like exposure time, pump power density and concentration of the dye for maximum fluorescent emission enhancement is found out.
• We suggest the deformation of the xanthene ring in Rh6G and the formation of a new intermediate state of the dye due to irradiation under optimum conditions.

Significant enhancement in the peak intensity of fluorescent emission has been observed in dye solution of Rhodamine6G in Methyl Methacrylate on irradiation with femtosecond laser pulses. Detailed studies have been carried out by varying the parameters like exposure time, dye concentration and pump power density to determine the optimum conditions for maximum fluorescent emission enhancement. Up to 30% increase in peak intensity has been found to occur with significant increase in fluorescent quantum yield. Fourier Transform Infra Red spectra recorded before and after irradiation reveal that xanthene ring in Rhodamine6G molecule gets deformed and a new intermediate state of the dye is formed before its gets deteriorated as the exposure time is increased well above the optimum value.