One dimensional tunable Coupled Resonator Optical Waveguide based on Liquid-Crystal layers

The tunability of one-dimensional Coupled Resonator Optical Waveguides (CROWs) composed of periodic arrangement of Liquid Crystals (LCs) and Si slabs is investigated, theoretically. The anisotropy of LC slabs is fundamental to form the propagation modes within the Photonic Band Gap (PBG), known as the defect mode, and is considered into the calculations by exploiting the 4 × 4 matrix representation of transfer matrix proposed by Yeh. Moreover, varying the electric field applied to LCs is an essential real-time tool in order to change the frequency of defect mode and, hence, turning the device to a tunable one. Several CROW structures are introduced and characterized by means of their PBG.