Fiber optical parametric amplifiers and wavelength converters for next-generation optical networks

Advances in fiber optic technology have resulted in connecting the globe with high-speed services at competitive cost. Currently the main capacity bottleneck is in access network. Advances and penetration of access networks will undoubtedly propagate more traffic to wards the network core, placing increasing strains on the existing backbone infrastructure. Next-generation core optical networks will require significant improvements in capacity and reconfigurability to accommodate the increased demand.; Fiber optical parametric amplifiers (OPA) could potentially play a role both in network reconfigurability and capacity enhancement. A fiber OPA relies on the third-order nonlinear susceptibility in fibers. In OPAs, when an optical signal co-propagates in a fiber with a strong pump, energy is transferred from the pump to the signal and a new wavelength component, the idler, is generated. OPAs can exhibit high gain and wide bandwidths and may find applications as versatile optical amplifier and wavelength converters.; Several key issues must be solved for fiber OPAs to become practical as amplifiers and wavelength converters. One major issue with fiber OPAs is the signal and idler spectra overlap when a densely populated and wide WDM spectrum is present at their input, covering their entire bandwidth. In this dissertation novel methods for modifying the basic OPA configuration in order to use the entire gain bandwidth is demonstrated. Another issue with fiber OPAs is their inherent polarization dependence. A polarization-independent two-pump OPA based on polarization diversity technique in a fiber loop configuration was experimentally demonstrated achieving sub-decibel polarization dependent gain over its entire gain bandwidth. A format-transparent pulsed-pump OPA for signal amplification and multiple wavelength conversion is also demonstrated. When an OPA is operated in high-repetition-rate pulsed mode, higher gain and wider bandwidths can be achieved as compared to continuous-wave OPAs with the same average pump power. Distributed parametric amplification for transmitting communication signals over an experimental fiber communication link is finally investigated. Low-penalty transmission of a 10-Gb/s communication signal along a 75-km transmission fiber with only 66.5 mW of pump power was achieved. Distributed parametric amplification provides a novel means of signal amplification and may find applications for single- or multi-channel systems.