Optoelectronic router based on a liquid crystal waveguide

A novel configuration for an optoelectronic integrated router based on a waveguide with a liquid crystal over-layer, working at the wavelength of 1.55 micron, is theoretically discussed for the first time. The device is based on the mode-mixing principle together with the electro-optic effect of a smectic A * liquid crystal. The device is composed by a single mode input optical channel waveguide, a bimodal active region, with a liquid crystal over-layer as cover, and an output Y branch to separate the two output channels. The active region is designed to allow a pi shift between the two modes that it supports, by means the variation of the effective refractive index of guided modes due to molecular reorientation of liquid crystals induced by an electrical field. By doing so it is possible to steer light from one output channel to the other one. Exhaustive detail about the design both of the input waveguide and of the active region has been given together with the description of the optical behavior of our device. Numerical simulations have shown how this kind of router exhibits satisfactory performances.