Spectroscopic and lasing properties of Xanthene dyes encapsulated in silica and polymeric matrices

The photo-physical properties of Xanthene dyes: Basic Rhodamine Yellow (BRY), Rhodamine590perchlorate (R590p), SulforhodamineB (SRB) doped in tetramethylorthosilicate (TMOS) and poly-methylmethacrylate (PMMA) are observed. The various parameters viz. full-width at half-maxima (FWHM), peak emission wavelength, quantum yield and excited state lifetime at different concentrations ranging from ∼0.05 to ∼1 mM of the dye under excitation by Copper Vapor Laser (CVL) of high repetition rate (∼5.6 kHz) of are investigated. In order to identify photostability in dyes, normalized photostability has been studied and found that silica gel samples containing dye are more stable than that of polymeric samples. This has been further understood in terms of number density of unbleached dye molecules that infers that photobleaching of dye molecules is not prominent at higher concentrations in glassy solid matrices. Pump intensity dependent optical gain of the samples has also been reported and efforts have been made to study the efficiency of solid-state laser samples in a cavity for the performance of the dye laser.