Formation of light-guiding interconnections in an integrated optical circuit by composite tapered-film coupling

We demonstrate a new and simple method of forming light-guiding interconnections in an integrated optical circuit. This involves bridging the devices with a thin film having tapered ends that form naturally during the deposition process. Experiments show that there is no specific requirement for the thickness, refractive index, or relative position of the bridging film. A theory of composite waveguides provides an understanding of these interconnections.