Both gain transient and dynamic gain control devices were also designed and fabricated as photonic integrated circuits (PICs). Silicon-based PICs were able to perform dynamic gain tilt compensation by thermo-optic effect. Helium doped SOI rib waveguides were used for power monitoring and is potentially used as monolithic gain tilt compensation device with arrayed waveguide grating (AWG). / Dynamic gain tilt induced by wavelength dependent gain of EDFA leads to power penalty in wavelength division multiplexed systems. Using optical filter with known spectral response, it is possible to detect dynamic gain tilt and a per-band compensation scheme using electronic variable optical attenuators. This was implemented for dynamic gain tilt compensation (DGTC). / Dynamic provisioning of bandwidth and re-configurable optical networks can potentially allow efficient and cost effective deliveries of services based on the actual bandwidth requirement. Optical add/drop multiplexers (OADM) and optical cross-connects (OXC) will be used for such networks but the dynamic provisioning of optical channels may introduce optical power transients because of the slow gain dynamics of erbium doped fiber amplifiers. In this dissertation, the potential problems on using Erbium Doped Fiber Amplifiers (EDFA) in future reconfigurable optical networks are studied and possible solutions are assessed. In particular, the problems of gain transient and dynamic gain tilt were studied experimentally and theoretically. / In saturated EDFA channel add/drop can produce average power fluctuations, in timescales in the microsecond range. The thesis describes how gain transients can be minimized in gain clamped EDFA by optimizing erbium concentrations of EDF. Both simulations and experiments demonstrate that highly doped EDF minimize the transient in gain clamped EDFA. For unclamped EDFA, all-optical feedforward constant output power compensation has been successfully demonstrated using electronic variable optical attenuator (EVOA). / Chan Po Shan. / "August 2006." / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1813. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

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

Fiber Bragg grating sensors have been constantly researched for the last ten years and have finally begun to find use in the commercial market. However, one of the major factors limiting their widespread use is their system cost. Their lightweight, flexibility, electromagnetic immunity, and small size make fiber Bragg grating (FBG) sensors feasible in hostile environments where electrical and mechanical sensors may not function effectively. These sensor systems utilize moderately expensive light sources and detectors at telecommunication wavelengths of 1300 nm and 1550 nm. These are the center wavelengths of the mass-produced FBGs and FBG phase masks. This thesis addresses the development of a lower cost short wavelength fiber Bragg grating strain sensor system using gratings written at 790 nm and 850 nm with the modified phase mask method recently developed at Oregon State University. Short wavelength gratings allow the use of less expensive semiconductor sources and silicon detectors, greatly reducing the overall cost of a strain sensor system from approximately $1600 for a 1300 nm system to $1000 for a 790 nm system. First, the fundamental properties and historical background of fiber Bragg gratings were reviewed. Followed by a literature review of the structures, fabrication methods, and applications of FBGs including sensor applications. The design, manufacture, and assembly of the new short wavelength strain sensor system were described including the production of pigtailed super-luminescent edge emitting light emitting diodes (SELED) from commercial laser diodes, a fiber recoater, and multiple attempts to write a fiber Bragg grating in the 750-850 nm wavelength region. Finally, the short wavelength strain sensor system was compared with a 1300 nm strain sensor detailing the potential cost savings with the short wavelength system. / Graduation date: 2003

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xiii, 97 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 72-74).

v Abstract This study was developed using fiber drawing tower to fabricate various types of capillary fiber and microstructured fiber. For example, different diameter sizes, different thickness, different internal diameter ratio of the capillary fiber and capillary tube, single ring and double ring hexagonal arrangement of the air-holes microstructured fiber. Trying different ways to create complex structures preform, we use the stack - drawing - cutting way, is now able to produce only simple pressure can be achieved by the complex structure of the preform, compared to drilling way, we can effectively reduce the production costs of 80%. Now successfully produced a single ring and double ring hexagonal air holes arranged in preform which has been drawn into standard fiber. Depending on the optical properties, we can use quartz tube with a row of self-developed method to produce most of the complex structure of the preform. However, each fiber is still not very uniform about the pores, which we need to improve in the manufacturing process of fiber drawing. Produce more diverse system and much homogeneous microstructured fiber as the goal. Application is to use the self-fabricated capillary tube, after processing, the production target into a low-loss device, then inject different materials within the devices, and do the different optical measurements for our devices.

People to feel more and more attention to health, the pursuit of high quality of life, biomedical sensing is one of the development of technology, person to understand the current state of health, currently known as blood sugar and blood pressure monitors, to track health status of the instrument is obvious too inadequate, usually go to the hospital for examination, but it is quite time-consuming, ranging from a waste of time, so the immediate biomedical optical fiber sensor to do direction. Evanescent wave ways to do research for my use of the sensing material-specific dye, sensing agent in different situations will be absorbed to change the situation, the use of sol-gel method (Sol-Gel) to coated with the specific dye, to make our fiber clothes (cladding), when the light in optical fibers, through the specific dye to change the energy of light in optical fibers.

The dielectric ridge waveguide is an important passive component used in the optical communication system. Compared to its cousins¡Xthe buried ridge waveguides, it is less expensive to process but harder to design due to its inherent complex field structure (it has a larger index contrast between the core and the cladding). Therefore, it is crucial to develop an efficient and accurate method to analyze the modal characteristic of ridge waveguides. We began with the expansion of one-dimensional three-layer dielectric slab waveguide using simple orthogonal basis functions. We examined both the step-index profile and the graded-index profile waveguides to confirm the feasibility of this method and to understand the level of accuracy our technique can reach. We then proceeded to derive the vector formulation of two-dimension dielectric waveguides and compared our results against the exact numerical solutions of optical fiber modes using Bessel functions. Our 2-D Cartesian mode solver gave up to 6 significant digits of the fiber propagation constants. Finally, for rectangular dielectric waveguides, we use the tensor product of 1-D guiding-mode bases as an improvement over the simple orthogonal bases to speed-up the numerical convergence and cut the storage requirement by a factor of ten without loss of accuracy which is around 4 to 5 digits over a wide range of parameters and mode types. We will use these bases to solve for the mode field distribution of ridge-waveguides and other complex structures.

The effects of different ferrule length and epoxy layer thickness of the module of optical fiber connector under thermal cycling are investigated in this thesis. The finite element method package, MSC. MARC, is used in this study and the coupled thermal-elastic-plastic model is employed in the analysis. The mechanical behavior and life prediction with different length of ferrule and thickness of epoxy layer are considered. It is shown that the thickness of epoxy layer has the major effect on the life of the module. The stress and strain in the fiber and epoxy layer are decreasing with increasing of ferrule length, and the life of the module is increasing with increasing of thickness of epoxy layer. Finally, we recommend the ferrule length can be designed between 7.89mm ~10.5mm.

No description available.