Two-dimensional tunable metallic photonic crystals infiltrated with liquid crystals

We have investigated the effects of liquid crystal (LC) infiltration on the photonic band gaps (PBG's) of two-dimensional (2D) arrays of metallic rods. Contrary to the LC-infiltrated dielectric photonic crystals, the infiltration of LC's into metallic arrays enlarges PBG's and creates another PBG's. The change of refractive index due to the phase transition of LC's affects both edges of PBG's so that the positions of PBG's show rather large temperature dependence near the phase transition temperature. Thus metallic arrays infiltrated with LC's can overcome the drawbacks of LC infiltration in dielectric photonic crystals, i.e., the band gap narrowing and weak tunabilty of band gap. The usefulness of LC infiltration in the implementation of 2D or 3D tunable metallic photonic crystals is also discussed.