Liquid-crystal tunable long-range surface plasmon polariton waveguides and directional couplers

Long Range Surface Plasmon Polariton devices tuned by means of the electro-optic effect in liquid crystal are numerically investigated. Waveguides and 2x2 directional couplers, both in vertical and coplanar configuration are discussed. Application of a control voltage allows modifies the dielectric tensor profile and allows for the control of the devices, with low power consumption, high extinction ratio and insertion loss as low as 1 dB.