Tunable light propagation in photonic Crystal coupler filled with liquid Crystal

We propose a new photonic crystal coupler-type optical switch which consists of a triangular lattice of air holes filled with liquid crystal (LC). This switch utilizes the decoupling nature. In order to utilize a large refractive index change of LC, π phase-shifted larger air holes are introduced into the core region, compared to the cladding region. In our structure, all air holes are filled with LC and selective injection of LC is not required. By changing the orientation of the applied field, the coupling state changes decoupling from perfect coupling, and switching operation is realized. Switching operation of the present switch is confirmed by the two-dimensional finite-element method (FEM), and also preliminary three-dimensional calculations confirm the two-dimensional FEM results.