Font Size: a A A

Optical Network Based On Quantum Dot Semiconductor Optical Amplifiers, Optical Signal Processing Technology

Posted on:2010-12-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:H N HanFull Text:PDF
GTID:1118360278965448Subject:Electromagnetic field and microwave technology
Abstract/Summary:PDF Full Text Request
Due to the widespread use of the Internet and the availability of high-bandwidth services, the conventional Telecommunication Network faces new challenge, which is how to integrate the immense bandwidth of optical transmission technology with the new data services borne efficiently and agilely by the Internet Protocol (IP) switching technology. The optical packet switched network (OPN) is thus introduced to solve the problem.The OPN supports multi-granularities services and improves the bandwidth utilization, because the smallest switching granularity is optical packet and the bandwidth is allocated agilely according to the consumers' demands. Ultrahigh speed optical components are then required to fulfill these functions. Quantum dot (QD) based devices, especially quantum dot semiconductor optical amplifiers (QD-SOA) are advantageous compared to devices based on conventional bulk or quantum well gain media. That explains the motivation of our efforts into the research.This dissertation aims to tackle several tough issues in OPN, such as switching architectures and crosstalk, all-optical logic devices and ultrahigh speed all-optical wavelength converter.It first presents an introduction of the current state of the art in OPN.In chapter 2, a detailed analysis of the properties of QD material and the advantages of QD-SOA compared to conventional SOA is presented for the first time from the view of its applications in OPN. Then the three-level rate equation model is introduced, and the gain dynamics of QD-SOA is analyzed based on the model.Based on a crosstalk coefficient model, the crosstalk in QD-SOA switch gate based on XGM is studied in chapter 3. We use a traffic model to describe the difference of balanced and unbalanced traffic in OPN node. Crosstalk-induced bit error rate (BER), switching node dimension and switch cascaded capability under unbalanced traffic are examined, which prove to be relevant to the QD-SOA parameters the signal parameters and the traffic model unbalanced degree.In chapter 4, an ultra-fast all-optical XOR gate using quantum dot semiconductor optical amplifier-based Mach-Zehnder interferometer (QD-SOA-MZI), is studied through analytical method and numerical simulations, in searching of the optimal parameters and the suitable operation condition. Then several rules on the parameter design are drawn.Proposed and demonstrated in chapter 5 is a novel scheme of 160Gb/s all-optical AND gate. The effect of XGM in QD-SOA is employed in realizeing the AND operation. The design parameters have been analyzed and optimized to improve the system performance.In chapter 6, first, a scheme of ultra-fast wavelength conversion based on quantum dot semiconductor optical amplifier-terahertz optical asymmetric demultiplexer (QD-SOA-TOAD) is presented. The impact of critical parameters on the system performance is studied through numerical simulation and optimal parameter values are obtained. Second, the impact of ASE noise on a quantum dot semiconductor optical amplifier-delay interferometer (QD-SOA-DI) wavelength conversion scheme is discussed by introducing a method of equivalent noise source. The numerical simulation results show that the system performance will be deteriorated when the ASE noise is included and it could be improved by optimizing the parameters .
Keywords/Search Tags:Optical Packet Switching, Quantum Dot Semiconductor Optical Amplifier, Crosstalk, all-optical logic gate, wavelength conversion
PDF Full Text Request
Related items