Patent ID: 6345131
Filing Date: 2002-02-05
Classification: G02F

Abstract:
A thermo-optic switch having input and output terminals respectively connected to optical fibers, comprising:a substrate having etched portions at regions respectively corresponding to the input and output terminals; a lower clad layer formed over the substrate, the lower clad layer having an input taper formed at the region corresponding to the input terminal and adapted to convert a circular mode, input from the optical fiber connected to the input terminal, into an oval mode having a rib shape, and an output taper formed at the region corresponding to the output terminal and adapted to convert the oval mode into a circular mode allowed to be input to the optical fiber connected to the output terminal; a core layer formed over the lower clad layer and provided with branched waveguides having a rib structure, the branched waveguides selectively receiving the oval mode from the input taper and outputting the received oval mode to the output taper; an upper clad layer formed over the core layer; and switching electrodes formed on the upper clad layer and selectively activated to apply heat to an associated one of the branched waveguides in such a fashion that an effective refractive index difference occurs between the branched waveguides, thereby causing the branched waveguides to selectively receive the oval mode from the input taper.