Abstract
Optical properties have been investigated in azobenzenc (Az) LB ultrathin films adsorbing cyanine dyes on silver thin films using attenuated total reflection (ATR) measurements. Az LB ultrathin films were deposited by the diffusion adsorption method. The Az LB films containing the dyes showed strong optical absorption bands in the visible light region and the absorption bands remarkably changed as the LB films were annealed. The ATR properties of the LB films after the heat treatments strongly depended upon the wavelengths of the lasers, and the real parts of the complex dielectric constants decreased as the wavelengths became shorter. The dispersion properties of the Kramers-Kronig relation calculated from the absorption spectra coincided with the experimental results. The properties are thought to be due to an anomalous dispersion caused by the strong absorption. The results are useful for optical applications of LB films with strong absorption bands.
