EMISSION LIGHT PROPERTIES FROM Ag/RHODAMINE-B LB FILMS DUE TO SURFACE PLASMON EXCITATIONS IN THE KRETSCHMANN AND REVERSE CONFIGURATIONS

摘要

Emission light from Ag/ Rhodamine-B (RB) Langmuir-Blodgett (LB) films due to surface plasmon (SP) excitations has been investigated using the Kretschmann configuration of the attenuated total reflection (ATR) method and the reverse irradiation of laser beam from air to the samples. The conventional photoluminescence (PL) of the RB LB films showed a broad spectrum and the peak wavelength was about 600 nm. In the reverse irradiation, emission light was observed through the prism, and the intensities and the spectra strongly depended upon the emission angle where the light was observed. The wavelengths of the emission light became shorter as the emission angles increased. The relation between the wavelength and the emission angle agreed with the resonant condition of excitations of SPs in the Kretschmann configuration of ATR method. It was concluded that the emission light was caused by excitations of multiple SPs at the Ag/RB LB films.