Optical switch

Abstract

Abstract PURPOSE:To obtain the optical switch of a low applied voltage without changing an optical length by providing an optical directional coupler consisting of two pieces of optical waveguides being adjacent to each other, which are formed in a projecting part of a dielectric crystal substrate, a pair of control electrodes installed in its upper part, and a pair of auxiliary electrodes installed in both sides. CONSTITUTION:Optical waveguides 11, 12 formed with a Ti film pattern by thermal diffusion in the projecting part of a crystal substrate 10 having a projecting part shape are disposed adjacently, and an optical directional coupler 15 is constituted thereby. On the optical waveguides 11, 12, control electrodes 13, 14 are disposed through a buffer layer 21, respectively, and also, on both sides of the projecting part, auxiliary electrodes 19, 20 are disposed in the vicinity of each optical waveguide 11, 12 so as to be opposed to each control electrode 13, 14. That is, by synthesizing each electric field by the control electrodes 13, 14 and the auxiliary electrodes 19, 20, an effective electric field component is increased and by symmetrizing an electric field distribution in the waveguide, the same refractive index variation can be realized by the low voltage.

Inventors

• 👤 Masaaki Iwasaki
• 👤 正明 岩崎

Bibliographic Details