Optical coupling module with self-aligned etched grooves and method for fabricating the same

Abstract

The present invention relates to an optical coupling module for optically coupling an optical fiber with an optical waveguide, and a method of fabricating the optical coupling module. In an optical coupling module for optically coupling an optical network with a planar lightwave circuit (PLC), an etched groove for disposition of the optical fiber and an etched groove for mounting of the optical waveguide are exposed using a mask having mask patterns that are aligned with each other, and then anisotropically etched. By doing so, the two grooves can be precisely aligned with each other at one time, compared with a conventional method in which an exposure process is carried out two or more times. Accordingly, an inexpensive structure having high optical coupling efficiency upon manual alignment can be obtained. In addition, since a tapered structure in which an inlet is larger than a body is employed in the optical waveguide, tolerance in vertical and horizontal alignment upon manual alignment can be broaden, resulting in improvement of optical coupling efficiency and facilitation of manual alignment. Furthermore, by utilizing a thick insulation film on the substrate or a thick insulation film of the optical waveguide itself as a board, a structure for allowing assembly into and application to a high-frequency electric-optical circuit can be obtained.