Abstract

The coupling of an array of optical fibers with waveguides has become an important technique with the advent of integrated-optical devices and is a key issue in evaluating their manufacturability and reliability. So far, some techniques have been developed for LiNbO₃ waveguides.¹,² We have designed structures for the coupling of single-mode optical fibers to polymer-based optical waveguides. A thin layerof polymethyl methacrylate (PMMA) is deposited on top of a silicon wafer coated with silicon dioxide to form a thin-film waveguide. An appropriate choice of cladding can suppress multimode loses in the waveguide by insuring singlemode operation. Matching the refractive indices of the fiber and the waveguide further reduces the reflection loses. The process of micromachining, the wet-chemical an- iosotropic etching of silicon, has been well developed.

© 1990 Optical Society of America