Optical switch

DETAILED DESCRIPTION The present invention has been accomplished in view of the above problems and has an object to provide an optical switch capable of achieving the reduction of drive voltage and an increase of a deflection angle by forming optical deflection elements using a material having the polarization dependence and a large electro-optic constant, and also, capable of reducing a loss which occurs due to the polarization dependence of the deflection angle.
In order to achieve the above object, an optical switch according to the present invention comprises: at least one input channel waveguide and a plurality of output channel waveguides; a first optical deflecting unit which deflects a light input to the input channel waveguide; a slab type optical waveguide unit through which the light deflected by the first optical deflecting unit is propagated; and a second optical deflecting unit which deflects the light passed through the slab type optical waveguide unit at a deflection angle symmetrical to that by the first optical deflecting unit, to guide the light to one output channel waveguide selected from the plurality of output channel waveguides.
The first optical deflecting unit and second optical deflecting unit in the optical switch each includes: a slab type optical waveguide formed by using a material having the polarization dependence and an electro-optic effect; input side upper electrode portions each of which is formed with at least one prism type electrode on a position of the optical input side on the top surface of the slab type optical waveguide; output side upper electrode portions each of which is formed with at least one prism type electrode on a position of the optical output side on the top surface of the slab type optical waveguide; a lower electrode formed on the bottom surface of the slab type optical waveguide; a drive circuit which applies voltages to the input side upper electrode portions and the output side upper electrode portions, to generate substantially equal electric fields between the input side upper electrode portions and the lower electrode, and between the output side upper electrode portions and the lower electrode; and a mode conversion element which performs the inter-conversion between TE/TM modes of the light being propagated through the slab type optical waveguide positioned between the input side upper electrode portions and the output side upper electrode portions