A new method is proposed for measurement of the film optical parameters. A p-polarized laser beam falls on the glass surface at θi, and two reflected beams with intensities Ia and Ib from the front and the rear surface of the glass are
detected. The characteristic of the angular modulation of reflectance ratio γ ( γ =Ia/Ib) is closely related to the film optical parameters, namely refractive index nf, extinction coefficient kf and thickness df. By means of measuring the angle distribution γ(θi) and fitting the results with theoretical data, the optical parameters of the thin films can be obtained easily. Experimentally, we measured the exact optical parameters of tetra-neopentoxy phthalocyanine Zinc(TNPPcZn) LB films. In addition, the changes of optical parameters and absorption curves of TNPPcZn LB films in visible range at different annealing temperature were investigated. The results indicate that the changing tendency of the extinction
coefficient of TNPPcZn LB films obtained from these two methods were coincident. When the annealing temperature increased to 150°C, the monomer of TNPPcZn in LB films transformed to aggregate, nf and kf of the films increased. Further, nf and kf decreased as aggregate changed back to monomer again at 300°C.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.