Evanescent Waveguide and Photochemical Characterization of Azobenzene-Functionalized Dendrimer Ultrathin Films

Abstract

In this work we describe the evanescent waveguide characterization and photoalignment of azobenzene-functionalized dendrimer ultrathin films. Azobenzene dyes were grafted to the perimeter of polyamidoamine dendrimers. The photoisomerization and photoalignment properties were first investigated in relation to solution and film. The dendrimers were then blended with polystyrene, which served as a matrix for this investigation. Planar waveguides were prepared by spin coating on Au−BK7 glass substrates. The waveguides were investigated by ATR methods characterizing the s and p components of the waveguides. The refractive indices of the films were sensitively determined. The anisotropy of the dielectric constants were found to be highly dependent on the dendrimer/polystyrene ratio and aggregation properties.