Nonlinear and linear optical phenomena in silicon nanostructures : physics and applications

Thesis (Ph. D.)--University of Rochester. Dept. of Electrical and Computer Engineering, 2009.This thesis is devoted to a investigation of various nonlinear and linear optical phenomena in silicon nanostructures. The thesis starts with a thorough characterization of the third order nonlinearities for bulk silicon, in the near infra-red band, including their dispersion and anisotropy. This is the first complete study of silicon’s third order nonlinearity in this band, which offers guideline for the future work in this area. It then focuses on some examples of nonlinear phenomena inside silicon on insulator waveguides, including a theoretical discussion of four wave mixing and the observation of the formation of optical soliton. Thereafter, the thesis discusses another important application of silicon nanostructures based on linear processes, specifically silicon electrical-optical modulator. A closed-form model for the design and optimization of conventional capacitor based EO modulator is offered first. Then a novel design for a photonic crystal resonator based EO modulator is presented. Compared to the classical Mach-Zehnder and ring resonator structures, this design is more compact and suitable for integrated applications. The design of a hybrid Si photonic crystal EO polymer modulation is presented, together with a detailed fabrication process of the proposed structure followed by some measurement results