Low-Loss Coupling of Ribbon Fibers to Silica-on-Silicon Integrated Optics Using Preferentially Etched V-Grooves,

Abstract : Future advanced communication systems are likely to require complex passive optical components with many input and output, ports. Such components include M x N couplers, high density wavelength multiplexers, optical amplifiers etc. Traditionally, these components have been constructed using fused fibre coupler or micro-optic technology. These devices tend to be hand made and therefore expensive. Integrated optics technologies are more suitable for low cost mass production using fabrication technologies developed for the silicon integrated circuit industry. The most expensive part of the production of integrated optics devices is then fibre interfacing and packaging. A wide range of devices have been demonstrated using silica-on-silicon integrated optics technology. We have developed a process in which etched V-grooves are precisely defined in a silicon substrate on which silica waveguides and integrated optics devices are formed. Alignment tolerances of better than 1 micrometer are achieved, leading to low loss passively aligned coupling. To our knowledge, we are the first group to achieve this result. This paper reports the fabrication technique and the results of single and multiple fibre coupling.