Experimental Realization and Theoretical Studies of Novel All-optical Devices Based on Nano-scale Waveguides

Abstract

A novel all-optical switching device, being termed as photonic transistor (PT), which utilizes the optically induced gain and absorption change to manipulate the interference characteristics in a 2-waveguide directional coupler, was recently proposed. Initial theoretical studies show high-speed all-optical switching with switching gain and substantially lower power than the SOA approach can be realized based on the new switching scheme, which will benefit next-generation ultrafast and power-efficient optical network. However, systematical studies and experimental realization of PT have been lacking. In this dissertation, parametric analysis of the PT switching performance is carried out based on a new analytical method developed, highlighting the important device design aspects that have never been raised before. Experimental realization in an integrated platform is achieved for the first time with different fabrication approaches being developed. Two new PT architectures based on three-waveguide directional coupler and MZI are proposed to alleviate the fabrication challenges posed to the initial design. Lastly, optical studies of the devices fabricated are performed and switching gain is demonstrated in a single-waveguide structure.