| The first part of the thesis focuses on the design and investigation of modulation formats. Optical single sideband designs are proposed to increase the spectral efficiency. There are two approaches to generate optical single sideband. The first approach uses dual- electrode Mach Zehnder modulators to mimic the Hilbert transform to generate single sideband signals. The optical carrier can be suppressed in the first approach. The second approach uses Fiber Bragg Grating devices to filter out the unwanted sideband. The second approach can achieve chromatic dispersion at the same time. The thesis also compares the modulation formats' tolerance against fiber impairments, such as chromatic dispersion and polarization mode dispersion. Experimental results show that the Return-to-Zero, Vestigial sideband format is the most tolerant to the combined 1st order polarization mode dispersion and residual chromatic dispersion.; The second part of the thesis focuses on increasing the capacity and efficiency of optical access networks. First, a new medium access control protocol is proposed to improve the efficiency of Ethernet-based passive optical networks. This protocol also improves the quality of service parameters of the passive optical networks to support various applications. The fairness issues of medium access control are also addressed, and a media access control protocol that supports fairness is designed. Second, a new hybrid wavelength/time division multiplexing optical access network architecture, SUCCESS, which stands for Stanford University aCCESS, is proposed. This architecture provides a smooth path for migration from current passive optical networks to high capacity dense wavelength division multiplexing optical access networks. The network is both economical and efficient, and it can provide protection and restoration capabilities. |
