Abstracts Category : Other

Polarization and fiber nonlinearities

by Qiang (1973 Lin

This thesis is devoted to a thorough investigationof various nonlinear phenomena in optical fibers over a variety oflength, time, and power scales. It presents a unified theoreticaldescription of fiber nonlinearities, their applications, existingproblems, and possible solutions, particularly focusing on thepolarization dependence of nonlinearities. The thesis begins withan investigation of quantum-correlated photon pair generation inthe extremely low-power regime, and fundamental quantum noiseproperties of dual-pump parametric amplfiers in the very high gainregime. It then focuses on two experimental demonstrations ofapplications based on four-wave mixing: an ultrafast all-opticalswitching scheme with the capability of multi-band wavelengthcasting, and a subpicosecond parametric oscillator with broadbandtunability. The thesis next deals with the theoretical andexperimental investigation of a novel phenomenon of vector solitonfission during supercontinuum generation in a tapered fiber in thefemtosecond regime. The vectorial nature of Raman scattering isdiscussed next. In particular, I propose a vector form of the Ramanresponse function to descibe accurately the Raman-related phenomenaduring ultrashort pulse propagation inside optical fibers. Thethesis also presents a unified theory to describe nonlinearities inlong fibers with random birefringence and polarization-modedispersion. It focuses on the statistical nature of theinteractions between random polarizaiton-mode disperion and variousnonlinear effects like stimulated Raman scattering, cross-phasemodulation, four-wave mixing, and self-phase modulation. Inparticular, I quantify their impacts on various nonlinear photonicfunctionalities such as Raman amplification, nonlinear opticalswitching, parametric amplfication, wavelength conversion, solitonstability, etc.