本文提出一种新颖的动态全光网络监控分布式算法，该算法可估计光网络中光纤链路上的误码率，在不需要额外光监控元件的情况下同时监控，检测和定位多处光纤链路损坏。 / 在光网络传输过程中，各个终端结点的接受机可以时时地估计出收到光流的误码率，这些误码率信息可以通过扩展OSPF-TE协议在全网共享。基于这些共享的误码率信息，我们将光纤损坏检测问题抽像成一个线性编程（LP）算法，其中每一个误码率信息代表一个限制条件。我们之后运用一些算法优化技巧将这个问题的维度和复杂度大大地降低，以便可以直接嵌入到每个网络结点可能自带的微处理器单元中进行实时计算运用。本文提出的算法同时适用于没有光波长转换器的光网络和配备光波长转换器的光网络。 通过沿用OSPF协议的分层多域思想，大规模网络可以分化成小的域和连接各域的主干网络，从而可以将一个复杂的大规模网络检错问题转化成一系列简单小网络检错问题。通过将该算法在一个由408 节点组成，支持40波长的大规模GMPLS 网络仿真平台上仿真，算法的有效性得到了验证。 / 为了保证用于仿真的网络流量模型合理且符合实际，本文也对动态全光网络流量模型做了一定研究。在自相似网络流量模型下，我们发现长短光流的不公平性问题可以给动态全光网络带来很大问题，会大大地降低网络的吞吐率。我们运用一种截短长光流的方法可以将这个问题很有效地解决。 / 据我们所知，这是目前唯一的一个能运用于现实中超大规模光网络的低成本可实现且可以作到波长级监控和同时监控多个链路错误的算法。该方法可以不用额外添加昂贵的光监控元件就可实现对动态全光网络的监控，并且该方法同时适用于透明，半透明及配置波长转换器的光网络。 / A new and efficient distributed algorithm for estimating the bit-error-rate (BER) of links in dynamic optical networks is proposed. The method can be used to monitor, detect and localize multiple soft link-failures without incurring any additional optical monitoring equipment. During the transmission of each optical flow the end node’s receiver can estimate the digital BER information, and the BER information can be shared among the network by extending the Open Shortest Path First-Traffic Engineering Extension (OSPF-TE) protocol easily. We model the faults localization problem as a linear programming (LP) algorithm, where each BER information measured from a flow serves as a constraint. Optimization techniques are applied to significantly simplify the complexity of the LP algorithm in order to make it solvable in real time by an integrated processor attached to the network node. The proposed algorithm is capable of monitoring networks with or without wavelength converters. A large scale network can be divided into several layers according to the OSPF protocol, thus the algorithm can be applied to large networks in the real world similar to OSPF. The monitoring algorithm is demonstrated by network simulations over a 408-node, 40-wavelength network test-bed where up to twenty faulty links are identified. / To make sure the traffic generator model is reasonable, the traffic model for dynamic all-optical network is also studied in this work. Under self-similar traffic, we found that the dynamic optical networks suffer from the long flow short flow unfairness problem, which would reduce the throughput as well. So a segmentation strategy is proposed to solve this problem. / To the best of our knowledge, this is the first realistic and low-cost framework which can monitor channel level BER changes to identify multi-link-failures efficiently for large scale dynamic all-optical WDM networks, without using expensive optical monitors or additional supervisory channels. The approach proposed is applicable to transparent, translucent and wavelength-converted optical networks. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Huadong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 64-66). / Abstracts also in Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Backgrounds --- p.11 / Chapter 2.1 --- ROADMs, Dynamic networks --- p.11 / Chapter 2.1 --- Types of failures considered: --- p.13 / Chapter 2.2 --- Brief review of OSPF routing protocol --- p.15 / Chapter Chapter 3 --- Traffic model used --- p.16 / Chapter 3.1 --- Introduction --- p.16 / Chapter 3.2 --- LFSF unfairness problem --- p.19 / Chapter 3.3 --- Flow segmentation strategy --- p.23 / Chapter 3.4 --- Simulation results --- p.24 / Chapter 3.5 --- Summary and Conclusion --- p.29 / Chapter Chapter 4 --- Estimated digital BER monitoring and faults diagnosis algorithm --- p.31 / Chapter 4.1 --- Intra-domain faults diagnosis algorithm --- p.31 / Chapter 4.2 --- Hierarchically layering scheme for inter-domain network monitoring --- p.37 / Chapter Chapter 5 --- Simulation results and analysis --- p.40 / Chapter 5.1 --- Simulation set up --- p.40 / Chapter 5.1.1 --- 100Gbps simulation set up --- p.40 / Chapter 5.1.2 --- 10Gbps simulation set up --- p.42 / Chapter 5.2 --- Simulation results --- p.44 / Chapter 5.2.1 --- 100Gbps simulation results: --- p.44 / Chapter 5.2.2 --- 10Gbps simulation: --- p.51 / Chapter 5.3 --- Conclusion --- p.61 / Chapter Chapter 6 --- Conclusion --- p.62 / Reference --- p.64

Chong, Kin Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (p. 58-63). / Abstract also in Chinese. / Acknowledgement --- p.i / Abstract --- p.ii / 摘要 --- p.iv / Table of contents --- p.vi / List of figures and tables --- p.viii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1. --- Overview of optical regeneration --- p.1 / Chapter 1.1.1. --- O-E-O regeneration --- p.3 / Chapter 1.1.2. --- All-optical regeneration --- p.5 / Chapter 1.2. --- Motivation of this thesis --- p.7 / Chapter 1.3. --- Outline of this thesis --- p.9 / Chapter Chapter 2 --- Previous schemes of all-optical regeneration --- p.10 / Chapter 2.1. --- Introduction --- p.10 / Chapter 2.2. --- Fiber-based all-optical regeneration --- p.12 / Chapter 2.2.1. --- SPM-based regeneration --- p.12 / Chapter 2.2.2. --- FWM-based regeneration --- p.15 / Chapter 2.3. --- Semiconductor-based all-optical regeneration --- p.18 / Chapter 2.3.1. --- XGM-based regeneration --- p.18 / Chapter 2.3.2. --- XAM-based regeneration --- p.20 / Chapter 2.4. --- Multi-wavelength regeneration --- p.22 / Chapter 2.5. --- Summary --- p.23 / Chapter Chapter 3 --- Multi-wavelength optical 2R regeneration utilizing self-phase modulation and inter-channel walk-off control in fiber --- p.25 / Chapter 3.1. --- Introduction --- p.25 / Chapter 3.2. --- System architecture of the regenerator --- p.27 / Chapter 3.3. --- Experimental setup --- p.28 / Chapter 3.4. --- Results and discussions --- p.32 / Chapter 3.4.1. --- Effects of the improper inter-channel walk-off --- p.35 / Chapter 3.4.2. --- Effects of the improper filter offset --- p.36 / Chapter 3.5. --- Summary --- p.39 / Chapter Chapter 4 --- Investigation of the scalability and cascadability of our proposed multi-wavelength regeneration scheme --- p.40 / Chapter 4.1. --- Introduction --- p.40 / Chapter 4.2. --- Simulation models and results --- p.41 / Chapter 4.2.1. --- 10x10-Gb/s scenario --- p.41 / Chapter 4.2.2. --- 4x40-Gb/s scenario --- p.47 / Chapter 4.3. --- Discussions --- p.51 / Chapter 4.4. --- Summary --- p.53 / Chapter Chapter 5 --- Conclusion and future works --- p.54 / Chapter 5.1. --- Summary of the thesis --- p.54 / Chapter 5.2. --- Future works --- p.55 / List of publications --- p.57 / Bibliography --- p.58

Shen, Dong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 98-106). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iv / Acknowledgements --- p.v / Table of Contents --- p.vi / Chapter Chapter 1 --- Background --- p.1 / Chapter 1.1 --- Translucent Optical Networks --- p.1 / Chapter 1.1.1 --- The Way Towards Translucent --- p.1 / Chapter 1.1.2 --- Translucent Optical Network Architecture Design and Planning --- p.3 / Chapter 1.1.3 --- Other Research Topics in Translucent Optical Networks --- p.6 / Chapter 1.2 --- Fault Monitoring in All-Optical Networks --- p.12 / Chapter 1.2.1 --- Fault Monitoring in Network Layer's Perspective --- p.12 / Chapter 1.2.2 --- Passive Optical Monitoring --- p.14 / Chapter 1.2.3 --- Proactive Optical Monitoring --- p.16 / Chapter 1.3 --- Contributions --- p.17 / Chapter 1.3.1 --- Translucent Optical Network Planning with Heterogeneous Modulation Formats --- p.17 / Chapter 1.3.2 --- Multiplexing Optimization in Translucent Optical Networks --- p.19 / Chapter 1.3.3 --- An Efficient Regenerator Placement and Wavelength Assignment Scheme in Translucent Optical Networks --- p.20 / Chapter 1.3.4 --- Adaptive Fault Monitoring in All-Optical Networks Utilizing Real-Time Data Traffic --- p.20 / Chapter 1.4 --- Organization of Thesis --- p.22 / Chapter Chapter 2 --- Regenerator Placement and Resource Allocation Optimization in Translucent Optical Networks --- p.23 / Chapter 2.1 --- Introduction --- p.23 / Chapter 2.2 --- Translucent Optical Network Planning with Heterogeneous Modulation Formats --- p.25 / Chapter 2.2.1 --- Motivation and Problem Statements --- p.25 / Chapter 2.2.2 --- A Two-Step Planning Algorithm Using Two Modulation Formats to Realize Any-to-Any Topology Connectivity --- p.28 / Chapter 2.2.3 --- Illustrative Examples --- p.30 / Chapter 2.2.3 --- ILP Formulation of Minimizing Translucent Optical Network Cost with Two Modulation Formats under Static Traffic Demands --- p.34 / Chapter 2.2.4 --- Illustrative Numeric Examples --- p.42 / Chapter 2.3 --- Resource Allocation Optimization in Translucent Optical Networks --- p.45 / Chapter 2.3.1 --- Multiplexing Optimization with Auxiliary Graph --- p.45 / Chapter 2.3.2 --- Simulation Study of Proposed Algorithm --- p.51 / Chapter 2.3.3 --- An Efficient Regenerator Placement and Wavelength Assignment Solution --- p.55 / Chapter 2.3.4 --- Simulation Study of Proposed Algorithm --- p.60 / Chapter 2.4 --- Summary --- p.64 / Chapter Chapter 3 --- Adaptive Fault Monitoring in All-Optical Networks Utilizing Real-Time Data Traffic --- p.65 / Chapter 3.1 --- Introduction --- p.65 / Chapter 3.2 --- Adaptive Fault Monitoring --- p.68 / Chapter 3.2.1 --- System Framework --- p.68 / Chapter 3.2.2 --- Phase 1: Passive Monitoring --- p.70 / Chapter 3.2.3 --- Phase 2: Proactive Probing --- p.71 / Chapter 3.2.4 --- Control Plane Design and Analysis --- p.80 / Chapter 3.2.5 --- Physical Layer Implementation and Suggestions --- p.83 / Chapter 3.3 --- Placement of Label Monitors --- p.83 / Chapter 3.3.1 --- ILP Formulation --- p.84 / Chapter 3.3.2 --- Simulation Studies --- p.86 / Chapter 3.3.3 --- Discussion of Topology Evolution Adaptiveness --- p.93 / Chapter 3.4 --- Summary --- p.95 / Chapter Chapter 4 --- Conclusions and Future Work --- p.95 / Chapter 4.1 --- Conclusions --- p.96 / Chapter 4.2 --- Future Work --- p.97 / Bibliography --- p.98 / Publications during M.Phil Study --- p.105

Zhao, Qiguang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 72-76). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Telecommunications network hierarchy --- p.2 / Chapter 1.2 --- PON architectures for access networks --- p.4 / Chapter 1.2.1 --- TDM-PON --- p.5 / Chapter 1.2.2 --- WDM-PON --- p.7 / Chapter 1.3 --- Motivation of this thesis --- p.8 / Chapter 1.4 --- Outline of this thesis --- p.11 / Chapter Chapter 2 --- Previous Internetworking Architectures for Optical Network Units in Passive Optical Networks --- p.12 / Chapter 2.1 --- Introduction --- p.13 / Chapter 2.2 --- Previous internetworking architectures with ONU-broadcast capability / Chapter 2.2.1 --- Virtual ring network construction --- p.14 / Chapter 2.2.2 --- Reflection mechanism employing a FBG --- p.15 / Chapter 2.2.3 --- Loop-back mechanism in TDM-PON --- p.16 / Chapter 2.3 --- Previous internetworking architectures with ONU-VPGs formation capability --- p.17 / Chapter 2.3.1 --- E-CDMA application --- p.17 / Chapter 2.3.2 --- SCM technique --- p.18 / Chapter 2.3.3 --- Reflective waveband grouping mechanism --- p.20 / Chapter 2.4 --- Previous protection scheme for internetworking architectures --- p.21 / Chapter 2.4.1 --- Local ring protection in TDM-PON --- p.21 / Chapter 2.5 --- Summary --- p.22 / Chapter Chapter 3 --- Novel Internetworking Architecture with ONU-Broadcast Capability in a WDM-PON --- p.24 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Network topology and wavelength assignment --- p.26 / Chapter 3.3 --- Operation principle --- p.27 / Chapter 3.4 --- Experimental demonstration --- p.31 / Chapter 3.5 --- Power budget and scalability --- p.34 / Chapter 3.6 --- Summary --- p.36 / Chapter Chapter 4 --- Novel Internetworking Architectures with ONU- VPGs Formation Capability in a WDM-PON --- p.37 / Chapter 4.1 --- Introduction --- p.38 / Chapter 4.2 --- Novel architecture with ONU-VPGs formation based on RF tone technique --- p.39 / Chapter 4.2.1 --- Introduction --- p.39 / Chapter 4.2.2 --- Network topology and wavelength assignment --- p.40 / Chapter 4.2.3 --- Media access control protocol: CSMA/CA protocol --- p.42 / Chapter 4.2.4 --- Experimental demonstration --- p.43 / Chapter 4.2.5 --- Discussion --- p.47 / Chapter 4.2.6 --- Summary --- p.49 / Chapter 4.3 --- Novel architecture with ONU-VPGs formation in optical layer --- p.51 / Chapter 4.3.1 --- Introduction --- p.51 / Chapter 4.3.2 --- Network topology and wavelength assignment --- p.51 / Chapter 4.3.3 --- Operation principle --- p.54 / Chapter 4.3.4 --- Experimental demonstration --- p.56 / Chapter 4.3.5 --- Discussion --- p.58 / Chapter 4.3.6 --- Summary --- p.65 / Chapter 4.4 --- Comparisons --- p.66 / Chapter 4.5 --- Summary --- p.67 / Chapter Chapter 5 --- Summary and Future Works --- p.68 / Chapter 5.1 --- Summary of the thesis --- p.69 / Chapter 5.2 --- Future works --- p.70 / LIST OF PUBLICATIONS --- p.71 / BIBLIOGRAPHY --- p.72

This thesis aims at both developing highly nonlinear Aluminum Gallium Arsenide waveguides(AlGaAs) and demonstrating all-optical wavelength conversion via cross-phase modulation in AlGaAs waveguides at telecommunications wavelengths. This work covers waveguide design, device fabrication, device characterization and system work.

This thesis aims at both developing highly nonlinear Aluminum Gallium Arsenide waveguides(AlGaAs) and demonstrating all-optical wavelength conversion via cross-phase modulation in AlGaAs waveguides at telecommunications wavelengths. This work covers waveguide design, device fabrication, device characterization and system work.

Photonic crystal (PC) technology potentially offers lossless control of light propagation at a size scale near the order of the wavelength of light. The advantages and benefits of using such a technology in commercial devices are staggering. Yet, the commercial development of PC structures has been slow. Challenges associated with the repeatable fabrication and testing of structures has been identified as one cause of the slow development pace. To address these challenges, a development methodology that utilizes PC structures operating in the long-wavelength infrared is presented. One-dimensional PC structures, consisting of alternating regions of silicon and air are fabricated and characterized by measuring the transmittance or reflectance of the structure over the wavelength range from 5 쭠to 15 쭮 For the measurements, a model of the focused infrared beam is developed, tested and employed to characterize the structures. A novel measurement method, enabling the calculation of the single-angle plane-wave transmittances and reflectances from composite, multiple-angle transmittance and reflectance measurements, is formulated, tested and applied to PC structures. A new spectral characterization tool using a discretely tunable carbon-dioxide laser is presented and demonstrated. A measurement apparatus employing an FTIR microspectroscopy system is developed and measurements are recorded for the single-angle plane-wave characterization method. Single-angle plane-wave transmittances and reflectances calculated from composite multiple-angle measurements are shown to be in excellent agreement with theory. The results of this research are analyzed to identify the advantages and limitations of the long-wavelength infrared method.

In present dissertation, field-driven quantum well (QW) device is proposed to obtain high-speed and high-efficiency all-optical wavelength converter (AOWC). A new type QW material, InGaAsP/InGaAlAs, is employed to improve not only quantum confined Stark effect, but also carrier life time during high electric field excitation. The bandwidth as well as efficiency can be enhanced. Thus, the slow gain recovery mechanism (~100ps) from conventional semiconductor optical amplifier (SOA)-based AOWC can be overcome. The dispersion- and efficient- limited fiber-based AOWC (~10ps) can also be avoided. -3dB frequency bandwidth exceeding 40GHz for both electrical-to-optical and photocurrent response has been observed from InGaAsP/InGaAlAs waveguide of AOWC, leading to above 40GHz bandwidth in optical-to-optical response. A 40 Gb/s measurement setup is finally used for testing eye-diagram and bit-error-ratio in order to verify the data transmission of AOWC. Low power penalty with 0.5 dB comparing with back-to-back system performance is measured, suggesting InGaAsP /InGaAlAs waveguide is applicable to all-optical processing. By exciting short optical pump pulse in such waveguide, as short as 6.4ps probe pulse is observed, breaking through 10ps order in conventional type of QW and thus indicating the plausibility of performing 100Gb/s all optical processing.

The subject of this dissertation is to use precision cutting and polishing techniques to fabricate thin-film filters(TFFs) with a thickness of less than 100 £gm, and to discuss their applications in Wavelength Division Multiplexing(WDM) systems. To demonstrate the feasibility of the proposed technology, Si benches with wet-etching V grooves for precision fiber positioning and saw-cutting U grooves for placing the TFFs were fabricated. The insertion loss of the bench at 1.55 £gm input lights is less than - 0.5 dB. In addition, the stress induced pass band variations of band-pass TFF for Coarse WDM(CWDM) applications were studied. The pass band width of the band-pass TFF is 20 nm. After reducing the thickness of the 1.5 mm ¡Ñ 1.5 mm BP TFF to a thickness of 50 £gm, the center wavelength shift and pass band reduction are 4.64 nm and 1.54 nm, respectively.

The bandgaps of semiconductors are decreased with increasing temperature which leads to the red-shift lasing wavelength of semiconductor lasers. Therefore, how to stabilize the lasing wavelength under different working temperatures becomes an important issue. The composition and size variation of quantum dots are additional factors which affect the lasing wavelength shift. It is well known that diffusion speeds up with increasing temperature and causes the wavelength shift to occur. To avoid the change of composition and size of quantum dots during growth, the suppression of the diffusion process is necessary to ensure the quantum dots to have a well preserved initial stage. The laser active region with InAs/GaAsN digital alloy quantum well structure was grown by molecular beam epitaxy in this experiment. The self-assembled quantum dots formed in the digital alloy quantum well under high stress. The carriers congregated in the lower energy levels with broadening distribution of composition and size of quantum dots. The peak wavelength shifted toward a longer wavelength with decreasing temperature. The behavior was contrary to the Varshni equation with shrinking bangaps under increasing temperature. Therefore, the sensitivity of the wavelength with temperature decreased. The size distribution of InAs quantum dots on the gradient quantum well broadened under higher arsenic pressure. Consequently, the wavelength sensitivity of quantum dots with temperature decreased. Finally, the InAs quantum dots were capped with the InAlAs quantum well to avoid the diffusion during high temperature growth. The capped InAs quantum dots prevented the wavelength shift from the composition and size variation of quantum dots. For the reason of stabilizing the lasing wavelength of the long wavelength semiconductor laser in optical communication system, it becomes an important topic to create new materials for the active region of the laser structure to avoid the lasing wavelength shift. The next generation temperature insensitive laser devices will be produced with the method which was created in this experiment.