Optical waveguide isolator

Abstract

Abstract PURPOSE:To eliminate the need for utilizing a magneto-optical effect and to provide the isolator which is smaller in size and has an excellent matching property by constituting optical waveguides formed by a proton exchange method into the optical path of an optical waveguide formed by a titanium diffusion method. CONSTITUTION:A lithium niobate crystal is used as a substrate and the proton exchange waveguide 2 and the titanium diffused waveguides 1, 3 are formed by the different production processes in the optical waveguide formed as a high-refractive index region on the substrate. The boundary in the juncture between the optical waveguides is so set that the boundary attains an angle thetasatisfying a total reflection condition with an abnormal optical refractive index and the other boundary is so set that the boundary is perpendicular to the progressing direction of the optical waveguides. The difference in losses by a difference in the progressing direction of the waveguides is increases by utilizing the total reflection of the light waves generated in the case of the progression from the high-refractive index region to the low-refractive index region in such a manner.

Inventors

• 👤 Takumi Fujiwara
• 👤 巧 藤原

Bibliographic Details