Self-alignment of optical fibers with optical quality end-polished siliconrib waveguides using wet chemical micromachining techniques

This paper presents a new cost-effective method for self-aligning optical f ibers on silicon platforms and for achieving optical quality end-polished s ilicon-on-insulator (SOI) rib waveguide devices using wet chemical micromac hining techniques, Through accurate alignment to the [011] plane(s) of the (100) device layer of a SOI wafer, rib waveguide devices with self-alignmen t features are fabricated with the ends of each waveguide wet etched and Co ncurrently polished providing an optical quality facet or fiber-to-waveguid e interface. Eliminating the need to saw cut and then mechanically polish t he ends of fabricated devices, the overall fabrication process is simplifie d whilst also providing an integrated optic fiber alignment capability at t he ends of the fabricated waveguide devices with an alignment accuracy limi ted by fiber size tolerance, Experimental measurements were carried out to verify the optical quality of the waveguide facets formed using this new te chnique which proved excess facet losses of practically unmeasurable quanti ties.