Laser and spectroscopic characterization of thin films

Transparent glass or polymer films doped by luminescent species are new promising materials for luminescent solar concentrators, wave guides, two dimensional lasers and nonlinear materials. Polymethylmethacrylate (PMMA) and Polyvinylacetate (PVA) films containing Rhodamine 6G (Rh6G) and glass films containing Rh6G and/or inorganic ions were prepared. Chemical and spectroscopic properties of the doped films were determined by means of absorption and polarized emission spectroscopy and lifetimes of the dopants. Thicknesses of the films were determined by laser interfero- metry and absorption spectroscopy in the visible and infrared. Simultaneously absorption spectra of the dyes uniformly dispersed in the film in a monomeric form were measured and the film thickness and homogeneity determined from the molar extinction coefficient of the dye. The films may be prepared with controlled and predetermined thickness. The nonlinear properties of the doped films may be enhanced during their formation by orienting the dopants either in an electric field or by stretching the films uni-axially. Fluorescence depolarization allows energy transfer measurements.