Modeling of polarization insensitive phase sensitive amplifier for phase regeneration

Abstract

This thesis describes a novel configuration which implements a polarization insensitive phase sensitive fiber optic parametric amplifier for phase regeneration. The proposed design can be used to address the inherent gain degradation issue in a polarization insensitive phase sensitive amplifier when polarization diversity loop is incorporated. This research investigates the possibilities for a significant gain enhancement when the polarization diversity loop is implemented. At first, a baseline for a phase sensitive amplifier scheme is developed by taking different parameters into consideration. In this case, an extensive characterization is carried out to identify the variations of phase sensitive fiber amplifier gain associated with the parameter changes. Once the baseline is developed, the polarization diversity loop is implemented in the phase sensitive amplifier in order to make the phase sensitive fiber amplifier insensitive to polarization state variations of the input signals. Moreover, the existing issues in the polarization diversity loop are identified. Finally, a strategic design is developed to overcome one of the major issues that persists in the existing polarization diversity loop configurations. It is the degradation of maximum achievable gain due to not being able to utilize the total pump power for parametric amplification process as only half of the pump power is available after polarization splitting at the input of the loop. The proposed design includes the concatenation of fiber pieces together to explore the possibility of gain enhancement of the diversity loop. To assess the performance of the proposed design, an extensive analysis is carried out. The gain enhancement introduced to the existing system is presented and suggestions are made for further improvements in the future.