| Over the past few years, DWDM has been widely adopted across the telecommunications industry to expand capacity in telecommunication infrastructure. The success of DWDM in increasing raw capacity on point-to-point fiber routes and the rapid growth of data communications accelerates the pace to all-optical networking. The goal of all-optical networking is to create a transparent optical layer that can easily manage the transport of signal entirely in the optical domain, reducing the need for processing and interpretation of signals, while increasing the reliability and restorability of high-bandwidth networks.; However, the premise of transparent or all-optical networks requires the availability of tools to measure and control the smallest granular component of such networks—the wavelength channel, not only in the transportation system, but also in core switching segments. This dissertation studied the optical performance measuring tools for WDM networks, and categorized the optical performance monitoring into two layers: optical-physical-layer performance monitoring and optical-path-layer performance monitoring. With potential mass-production capability for future wide range application, planar waveguide technology is selected as the focus of this dissertation.; In the optical-physical-layer, arrayed waveguide grating (AWG) based multi-channel wavelength, power and OSNR monitoring circuit were proposed. Modeling and design were performed to provide optimized performance. Multi-channel wavelength monitoring circuit was demonstrated with precise wavelength monitoring capability.; Optical-path-layer performance layer monitoring becomes necessary while optical cross-connect (OXC) is implemented. Focusing on one type of OXC, this dissertation studied the possibility to build a low cost, robust and transparent monitoring scheme using similar planar waveguide technology which been used in optical-physical-layer monitoring.; Furthermore, the applications of optical performance monitoring in all-optical networks were discussed, including system turn-up, dynamic gain spectrum flattening and power equalizing after OXC. |
