Metal coated, tapered, optical fiber coupled to substrate and method of

Abstract

The invention comprises an optical interferometer system utilizing optical fibers. Titanium is diffused into the surface of lithium niobate substrate to form an optical waveguide utilized by the interferometer. The central portion of the optical waveguide is divided into two substantially parallel sections. Grooves between and alongside the optical waveguide are etched into the surface of the lithium niobate to optically decouple the waveguide sections from each other and from the substrate. A first electrode is positioned between the parallel sections of the optical waveguide with second and third electrodes positioned alongside these sections. These electrodes are utilized to subject the optical waveguides to an electrical field to differentially modulate the velocity of optical energy in the parallel sections or waveguide in response to an electrical signal. This differential modulation of the velocity of optical energy permits enhancement of attenuation of the propagating light to develop in the waveguide. Along two edges of the optical interferometer, small shelves are formed in the ends of the substrate to expose the ends of optical waveguide. Optical fibers are tapered by selectively etching the cladding and the core. A metal layer is formed on the tapered portion of the cladding to prevent light from escaping from the optical fiber. Micro-positioners are utilized to position the exposed ends of the core adjacent the exposed ends of the waveguides and the optical fiber is affixed in this position with a material which adheres to both the optical fiber and the lithium niobate substrate.