Liquid crystal planar waveguide beam shifters: a comparative study

In this paper we propose a technical alternative to the implementation of a nalog multistage switches that use optical beam shifters, in which 2-inputs adjacent ports are interconnected to 2-outputs. The principle is based on the refraction of the extraordinary beam, in a planar liquid crystal wavegu ide, whose anisotropy can be electrically modified. We present here prelimi nary results and discuss the advantages and limitation of such a solution w ith respect to the conventional free-space switch based on the use of liqui d crystal polarization controllers, In particular, we show that this soluti on can present some interesting advantages with respect to telecommunicatio n system specifications, such as crosstalk, insertion losses and bandwidth range. Finally we discuss possible technical improvements and intrinsic lim itations.