Low-loss coupling to sub-micron thick deposited film rib and nanowire waveguides by vertical tapering

Abstract

The main purpose of this thesis is to present work towards theoretical and experimental characterization of a vertical taper-based spot size converter to increase the coupling efficiency between a single-mode fibre and rib and nanowire waveguides. Simulations of taper design parameters have been investigated in this thesis and optimised designs established for coupling to high numerical aperture fibres. These have then been experimentally implemented, and the techniques and fabrication processes have been discussed in detail. The experimental measurements of the finished devices are presented and analysis undertaken to determine areas for future improvement. Show more