Dispersion relations of surface plasmon polaritons with transverse-magnetic- and transverse-electric-polarized waves coexisting in insulator-metal-anisotropic planar waveguides are analytically derived. Aligned nematic liquid crystal, as an anisotropic medium, is employed to manipulate the mode properties. By varying its optical axis, two kinds of mode transformation are found: one is mode recombination, accompanied by dramatically extended propagation lengths at the cutoff angles, and the other is mode alternation, associated with an obvious shift of the electromagnetic energy flux from one insulator to the other. The results may have applications in actively modulated plasmon-based nanodevices and tunable surface plasmon sources.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)