| Internet traffic is expected to increase by a thousand times in the next ten years, which poses a severe challenge to the present optical transport network. To scale for future traffic, the optical network needs to handle higher data-rates while offer more flexibility. The most promising solution is a network based on the mixing of optical time-division multiplexing (OTDM), wavelength-division multiplexing (WDM), and photonic cross-connect (PXC) technologies that involve optical signal processing in the time, wavelength and space domains. At the same time, these technologies are required to achieve higher performance with lower cost and smaller size.; The goal of this dissertation is to meet the demands of future optical networks by developing compact and high-performance optoelectronic sub-systems using traveling-wave electroabsorption modulators (TW-EAMs). The optical signal processing capabilities studied in this dissertation include demultiplexing, add-drop multiplexing, and clock recovery for OTDM and wavelength conversion and 3-R regeneration for WDM. To ensure that the proposed approaches meet the demands in speed and functionality with the least amount of complication, the unique properties of the TW-EAM are explored and utilized in full to provide novel solutions. These properties include (1) the distributed effect due to the traveling-wave electrodes; (2) the photocurrent signal generated inside the device; (3) the nonlinear electro-optical transfer function of the TW-EAM; and (4) the integrability with other optoelectronic devices. Many resulting sub-systems have reached record operation speed and compactness. For example, the first 160-Gb/s OTDM add-drop multiplexing with a 40-Gb/s base-rate was demonstrated with TW-EAMs operated in the standing-wave enhanced mode, which is one of the new inventions proposed in this dissertation. Less than 1-dB of power penalty was achieved for all operations. On the other hand, a very compact optical 3-R regenerator was demonstrated by incorporating three essential functions (clock recovery, pulse generation, and nonlinear gating) into a single TW-EAM through the utilization of unique properties of the device. In addition, extensive numerical simulations are presented throughout the dissertation to model and study the proposed concepts. |
