The effect of light on a model colloidal beverage system under two different test conditions, refrigerated storage (14 d, 4°C) and accelerated storage at room temperature (12 hr, 25°C), was investigated. The addition of lutein to provide protection against photo-oxidation of susceptible compounds also was investigated. Fluorescent light-exposure (14 d, 4°C) of the control beverage system led to a decline in sensory quality based on triangle test results. Sensory quality also declined in the lutein-fortified beverage due to light-exposure. Sensory quality of light-exposed, lutein-fortified beverage compared to the light-protected control did not yield significant sensory differences for two out of three replications giving positive implications towards the use of lutein for photo-protection. Overall, panelists preferred beverages that were protected from light exposure with no specific preference towards control or lutein-fortified beverage, indicating lutein did not inhibit photo-chemical reactions leading to a decline in sensory quality. Chemical analysis showed limonene concentration was significantly higher in the lutein-fortified beverage compared to the control beverage after light exposure (14 d, 4°C). Hexanal concentration, however, was not closely correlated with sensory differences. Results of the accelerated storage (12 hr, 25°C) study showed that the most damaging wavelengths to lutein stability were UV (200-400 nm) and 463 nm wavelengths. Degradation of lutein at 463 nm was expected and can be attributed to lutein''s absorption of blue light at 450 nm. Hexanal formation was highest in the control beverage when exposed to full spectrum light and specifically UV (200-400 nm) wavelengths. Hexanal was also formed in the lutein-fortified beverage under full spectrum light and UV (200-400 nm) wavelength but to a significantly lesser degree. Limonene degraded significantly under all treatment conditions, with the most occurring during full spectrum light exposure. Lutein-fortification did not effectively protect limonene from degradation under these conditions. / Master of Science in Life Sciences

Optical networks employing wavelength division multiplexing technology have been well recognized as the core networks for the next generation Internet. In such networks, any fiber cut or node failure may lead to huge data loss. Thus, reliability is of great importance in the design of modern high-speed networks. At the same time, traffic grooming is another important design objective since it addresses multi-granularity traffic. The traditional routing approaches with differentiated services do not consider the traffic grooming case or reconfiguration method. Therefore, they are not resource-efficient for the next generation Internet. In this dissertation, an effective reconfigurable traffic grooming with differentiated reliability scheme is proposed to efficiently use network resources. Compared with the conventional rerouting method, the proposed scheme makes the network more robust and immune from service interruptions. An integer linear programming (ILP) formulation is presented first. By solving the ILP formulation, an optimal solution is obtained for each incoming connection request. However, the solution is so time consuming, a heuristic algorithm is introduced to get an approximate optimal solution. The performance evaluation indicates that the connection blocking probability can be decreased greatly by the proposed scheme.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / An edge-based hybrid finite element boundary integral (FE-BI) method using cylindrical shell elements is described for analyzing conformal quarter-wave patches embedded in a circular cylinder. Special care is also taken to deal with weight functions, dyadic Green’s function, and feed model. Some types of the patch arrays embedded in different circular radius have been developed. The tests of their VSWRs and radiation characteristics are in good agreement with the theoretical results.

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The emergence of new bandwidth-intensive applications articulated by distance learning, online gaming, Web 2.0 and movie delivery by means of high-definition video, has ultimately justified the necessity of upgrading the access network infrastructure to provide fat-bandwidth pipelines at subscriber close proximity. Passive optical networks (PONs) are an emerging technology to deliver these services. This thesis presents innovative work performed towards the application of coarse wavelength division multiplexing (CWDM) to route communications to and from reflective optical network units (ONUs) incorporated in time and wavelength division multiplexed PONs. The concept of coarse and dense WDM grid integration and its adaptation in access networks to map, for the first time, selective closely-spaced wavelengths into coarse passband windows of Gaussian and flat-top arrayed waveguide gratings (AWGs), exhibiting coarse-fine grooming, is initially developed. This is followed by the identification of a new network architecture combining multiple PONs, using a coarse AWG to form a next-generation access network. A significant feature of this approach allows for time division multiplexing (TDM) and WDM PON technologies to be integrated through the 7 nm coarse passband windows of a single AWG, providing for interoperability and high scalability. The network performance through simulation, in the presence of polarisation-dependent wavelength shift and associated polarisation-dependent loss, shows the capability of a single optical line terminal (OLT) to access various physical PONs in 25 km proximity with multiple wavelengths through a single AWG router. This approach enables centralised bandwidth allocation and a smooth migration path between time-shared and densely-penetrated access networks. Furthermore, to demonstrate full-duplex operation, allowing for increased bandwidth utilisation of the reflective access network architecture, full-duplex functionality is achieved by using polarisation division multiplexing. This is implemented in the OLT by assigning each ONU downstream data and continues waves on orthogonal states of polarisation. Hence, by assuming the use of symmetrical broadband services, the novel multi-PON access network verifies its potential to double the bandwidth utilisation for each subscriber, allowing for increased bidirectional network throughput. In addition, an experimental test-bed is performed which demonstrates the core operation of the network being, by means of a readily-available 2.7 nm-wide AWG router. Hence, the practical feasibility of the new access network concept is demonstrated.

Decoherence due to photon scattering in an atom interferometer was studied as a function of laser frequency near an atomic resonance. The resulting decoherence (contrast-loss) spectra will be used to calibrate measurements of tune-out wavelengths that are made with the same apparatus. To support this goal, a theoretical model of decoherence spectroscopy is presented here along with experimental tests of this model.

Jia, Wei. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 137-156). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

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Ku Yuen Ching. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 59-62). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview of optical networking --- p.1 / Chapter 1.2 --- Multi-wavelength optical networks --- p.3 / Chapter 1.2.1 --- Building blocks --- p.3 / Chapter 1.2.2 --- Performance limitations --- p.6 / Chapter 1.3 --- Related work about homodyne crosstalk --- p.8 / Chapter 1.4 --- The motivation of this thesis --- p.9 / Chapter 1.5 --- Outline of this thesis --- p.10 / Chapter 2 --- Crosstalk in WDM Networks --- p.11 / Chapter 2.1 --- Introduction --- p.11 / Chapter 2.2 --- Classification of optical crosstalk --- p.11 / Chapter 2.2.1 --- Nonlinear crosstalk --- p.12 / Chapter 2.2.2 --- Linear crosstalk --- p.13 / Chapter 2.3 --- Crosstalk characteristics --- p.14 / Chapter 2.3.1 --- Polarization states --- p.16 / Chapter 2.3.2 --- Wavelengths --- p.17 / Chapter 2.3.3 --- Phases --- p.17 / Chapter 2.4 --- Crosstalk mitigation techniques --- p.18 / Chapter 2.4.1 --- Manchester-encoding --- p.18 / Chapter 2.4.2 --- Bit-pattern misalignment --- p.19 / Chapter 2.4.3 --- Intra-bit modulation --- p.20 / Chapter 2.4.4 --- Phase scrambling --- p.20 / Chapter 2.5 --- Performance analysis --- p.21 / Chapter 2.5.1 --- Gaussian approximation --- p.22 / Chapter 2.5.2 --- Saddlepoint approximation --- p.24 / Chapter 2.5.3 --- Modified Chernoff bound --- p.25 / Chapter 2.5.4 --- Comparison --- p.26 / Chapter 2.6 --- Summary --- p.26 / Chapter 3 --- Optical Regeneration for Crosstalk Mitigation --- p.28 / Chapter 3.1 --- Introduction --- p.28 / Chapter 3.2 --- Optical regeneration techniques --- p.28 / Chapter 3.2.1 --- Fiber based gate --- p.30 / Chapter 3.2.2 --- Semiconductor based gate --- p.31 / Chapter 3.3 --- Crosstalk mitigation using SOA-MZI --- p.33 / Chapter 3.3.1 --- The experimental setup --- p.35 / Chapter 3.3.2 --- All-active SOA-MZI --- p.36 / Chapter 3.3.3 --- Results and discussion --- p.36 / Chapter 3.3.4 --- Summary --- p.39 / Chapter 3.4 --- Crosstalk mitigation using SPM spectrum filtering --- p.39 / Chapter 3.4.1 --- The experimental setup --- p.40 / Chapter 3.4.2 --- Results and discussion --- p.41 / Chapter 3.4.3 --- Summary --- p.44 / Chapter 4 --- Polarimetric Approach for Crosstalk Mitigation for Both 00K and DPSK Format --- p.45 / Chapter 4.1 --- Introduction --- p.45 / Chapter 4.2 --- Experimental setup --- p.46 / Chapter 4.3 --- Results and discussion --- p.47 / Chapter 4.4 --- Summary --- p.49 / Chapter 5 --- Crosstalk Accumulation Analysis --- p.50 / Chapter 5.1 --- Introduction --- p.50 / Chapter 5.2 --- Theory and model --- p.51 / Chapter 5.3 --- Results and discussion --- p.54 / Chapter 5.4 --- Summary --- p.56 / Chapter 6 --- Summary and Future Works --- p.57 / Chapter 6.1 --- Summary of the thesis --- p.57 / Chapter 6.2 --- Future works --- p.58 / Bibliography --- p.59 / Chapter A. --- Appendix A - List of publications --- p.63