Theoretical and experimental studies of surface plasmons excited at metal-uniaxial dielectric interface

In this letter, surface plasmons (SPs) excited at the metal-uniaxial dielectric interface are investigated both theoretically and experimentally. The dispersion relations of SPs are derived for the cases where the optical axis of uniaxial medium is parallel the interface or in the incident plane perpendicular to the interface. The theoretical predictions are verified by a Kretschmann–Raether [W. L. Barnes, A. Dereux, and T. W. Ebbesen, Nature (London) 424, 824 (2003)] configuration with azobenzene polymer as photoinduced uniaxial medium. The attenuated total reflection spectra clearly show that the dependence of the SPs propagation properties on the orientations of optical axis, which is consistent with the theoretical analysis. The results of this study provide a useful approach to modulate SPs through adjusting the azobenzene molecular orientation.