Electro-optical polarization controller based on solc filter in periodically poled lithium niobate

Polarization controller (PC) for optical fiber is a major area of study in the general field of coherent-optical communication systems. In communication systems based on single-mode, fiber, the states of polarization in fiber vary randomly due to temperature variations and mechanical perturbations along the fiber. These polarization changes can have a detrimental impact on polarization sensitive components. Recently, more and more research attentions have been paid to a new artificial nonlinear material: the periodically poled LiNbO3 (PPLN) because of its outstanding nonlinear optical properties. In this paper, we analytically proposed an electrical tuned polarization controller based on a single chip of Z-cut LiNbO3 crystal. The, first part is a Z-cut lithium niobate and the second part is periodically poled. The electric field is applied along the transverse and longitude directions for the separated part to implement the electro-optical polarization controller, respectively. With two electric fields applied by special control algorithms, the first part can. transform an incident light with arbitrary ellipsoid polarization into a linearly polarized light and the second part will turn this, linearly polarized light to a fixed linearly polarized light. Furthermore, if we use PPLN waveguide to fabricate such a device, only about 10V maximum driven voltage is needed for each stage, which is very attractive.