Properties Of Laser Dyes Research Articles

Spectral-luminescent and generation properties of rhodamine dyes in thin polymer films under optical excitation

A study was made of the absorption, fluorescence, and emission spectra of organic dyes Rhodamine 6Zh and Rhodamine C in thin (0.6–1.0 µm) layers based on methyl methacrylate-methacrylic acid copolymers formed by centrifugation on optically transparent glasses. The influence of a terbium salt on the properties of laser dyes in acrylic films was elucidated.

Spectral-Kinetic Properties of Laser Dyes in Active Elements on the Basis of Sol-Gel Matrices

The absorption and photoluminescence spectra as well as the photoluminescence lifetimes of laser dyes (Phenylamine 430, Rhodamine 6G, Rhodamine 6G zwitterion, Rhodamine 4C, and Rhodamine 101) in new matrices are studied. These matrices represent the hybrid of two types of porous glasses (microporous and sol-gel glass). Chemical transformations of the dye molecules in the matrices are not found. The dye dimers mentioned above are also absent for concentrations up to 10-4 M. The luminescence efficiencies of the dyes in the matrix and in the ethanol solutions are compared. The difference in concentration dependences of the photoluminescence spectrum of Rhodamine 6G in the matrix and ethanol solution is found and discussed. The collective emission of the dyes in new matrices is observed at a power density of exciting radiation of ∼1025 cm-2s-1 and a concentration of ∼10-4 M. The energies and collective emission spectra of the dyes in the matrix are compared with those in the solutions.

Effects of the Sol-Gel Processing on the Fluorescence Properties of Laser Dyes in Tetraethoxysilane Derived Matrices

Two fluorescent dyes were incorporated into sol-gel derived SiO2 matrices. The dye was added to SiO2 precursors of different degrees of pre-condensation and the spectroscopic properties of the immobilized dye were measured at various aging and drying stages of the resulting gels. The significant influence of the processing parameters on the spectroscopic properties is manifested in the relative intensity of a second red shifted emission band (550–560 nm), which was observed besides the typical coumarin emission band (495 nm). The appearance of this long wavelength emission might be attributed to dye aggregation or to other reactions with the ambient matrix forced by micro porosity phenomena.