Title of dissertation : SEMICONDUCTOR WAVEGUIDES FOR NONLINEAR OPTICAL SIGNAL PROCESSING

Title of dissertation: SEMICONDUCTOR WAVEGUIDES FOR NONLINEAR OPTICAL SIGNAL PROCESSING Paveen Apiratikul, Doctor of Philosophy, 2009 Dissertation directed by: Professor Thomas E. Murphy Department of Electrical and Computer Engineering This thesis investigates nonlinear effects in semiconductor waveguides for optical signal processing. Two semiconductor waveguides are studied : nanoporous silicon waveguide and GaAs/AlGaAs waveguide. First, nonlinear optical properties of nanoporous silicon waveguides including two-photon absorption, self-phase modulation and free-carrier effects are characterized and compared with similar measurements conducted on conventional silicon-on-insulator waveguides. Then, we experimentally demonstrate 10-Gb/s wavelength conversion using cross-amplitude modulation, cross-phase modulation and four-wave-mixing in GaAs/AlGaAs waveguides. Finally, we propose an ultrafast optical sampling system based on non-degenerate two-photon absorption in a GaAs photodiode. Using this technique, we successfully demonstrate a background-suppressed measurement of quasi 4-Tb/s eye diagrams. SEMICONDUCTOR WAVEGUIDES FOR NONLINEAR OPTICAL SIGNAL PROCESSING by Paveen Apiratikul Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park in partial fulfillment of the requirements for the degree of Doctor of Philosophy 2009 Advisory Committee: Professor Thomas E. Murphy, Chair/Advisor Professor Julius Goldhar Professor Mario Dagenais Professor Gary M. Carter Professor John T. Fourkas