Optical detection devices such as optical biosensors and optical spectrometers are widely used in many applications for the functions of measurements, inspections and analysis. Due to the large dimension of prisms and gratings, the traditional optical devices normally occupy a large space with complicated components. Since cheaper and smaller optical devices are always in demand, miniaturization has been kept going for years. Thanks to recent fabrication advances, nanophotonic devices such as semiconductor laser chips have been growing in number and diversity. However, the optical biosensor chips and the optical spectrometer chips are seldom reported in the literature. For the reason of improving system integration, the study of ultra-compact, low-cost, high-performance and easy-alignment optical biosensors and optical spectrometers are imperative. This thesis is an endeavor in these two subjects and will present our research work on studying the optical transmission properties of dielectric aperture arrays and developing new optical biosensors and optical spectrometers. / Subsequently, optical transmission properties through a self-mixing interferometer array are studied and a novel high-resolution cost-effective optical spectrometer is proposed. The miniature interferometer-based spectrometer is made of polymethyl methacrylate (PMMA) with a CCD as the detector. The detected intensity of each CCD pixels contains the spectral information. Since each frequency component in the incoming beam corresponds to a unique phase difference of the two beam portions of each optical interferometer, the total intensity received by each CCD pixel, which is resulted from the addition of the interference signals from all the frequency components in the beam, should also be unique. Therefore, the spectrum calculation is a problem to solve an ill-posed linear system by using Tikhonov regularization method. Simulation results show that the resolution can reach picometer level. Apart from the choice of path difference between the interfering beams, the spectral resolution also depends on the signal-to-noise ratio and analogue-digital conversion resolution (dynamic range) of the CCD chip. In addition, the theory of uniform waveguide scattering is explored to expand the possibility of using such mini-interferometers for performing free-space spectral analysis of waveguide devices. At the same time, the method of least squares is used to correct the pixel non-uniformity of the CCD so as to improve the performance of the spectrometer. / The first half of the thesis demonstrates that the optical phase shift associated with the surface plasmon (SP) assisted extraordinary optical transmission (EOT) in nano-hole arrays fabricated in a metal film has a strong dependence on the material refractive index value in close proximity to the holes. A novel refractive index sensor based on detecting the EOT phase shift is proposed by building a model. This device readily provides a 2-D biosensor array platform for non-labeled real-time detection of a variety of organic and biological molecules in a sensor chip format, which leads to a high packing density, minimal analyte volumes, and a large number of parallel channels while facilitating high resolution imaging and supporting a large space-bandwidth product (SBP). Simulation (FDTD Solutions, Lumerical Solutions Inc) results indicate an achievable sensitivity limit of 4.37x10-9 refractive index units (RIU) and a dynamic range as large as 0.17 RIU. / The sensor chip and spectrometer chip introduced here are based on the interference of light transmitted through dielectric aperture arrays. Their compact feature renders these devices ideal for miniaturization and integration as the systems in microfluidics architectures and lab-on-chip designs. / Yang, Tao. / Adviser: H. P. Ho. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 150-163). / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

by S.W. Wong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 76-77). / by S.W. Wong. / Title Page --- p.i / Dedication --- p.ii / Acknowledgments --- p.iii / Abstract --- p.iv / Table of Contents --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- A Brief Introduction to Nonlinear Optics --- p.7 / Chapter Chapter 3 --- Experimental Measurement of the First Hyperpolarizability β for pNA by Hyper-Rayleigh Scattering in Solution --- p.24 / Chapter 3.1 --- Introduction --- p.24 / Chapter 3.2 --- Theory of Measurement of β by HRS --- p.26 / Chapter 3.3 --- Experimental Setup --- p.31 / Chapter 3.4 --- Preparation of Sample --- p.34 / Chapter 3.5 --- Results --- p.35 / Chapter Chapter 4 --- Studies of Depolarization Ratio in HRS --- p.44 / Chapter 4.1 --- Background --- p.44 / Chapter 4.2 --- Theory --- p.45 / Chapter 4.3 --- Results --- p.55 / Chapter 4.4 --- Discussion and Conclusion --- p.57 / Chapter Chapter 5 --- Measurement on other Nonlinear Optical Compounds --- p.63 / Chapter Chapter 6 --- Conclusion --- p.73 / References --- p.76

Luk, Wai Chun = / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 101-108). / Abstracts in English and Chinese. / Luk, Wai Chun = / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Theoretical Background --- p.5 / Chapter 2.1 --- Maxwell´ةs equations in matter --- p.5 / Chapter 2.2 --- Dielectric constant of materials --- p.8 / Chapter 2.3 --- Dispersion relation of surface plasmon polaritons --- p.10 / Chapter 2.4 --- Excitation of surface plasmon polaritons --- p.16 / Chapter 2.4.1 --- Prism coupling --- p.17 / Chapter 2.4.2 --- Grating coupling --- p.21 / Chapter 2.5 --- Diffraction of light in gratings --- p.26 / Chapter 2.6 --- Applications --- p.27 / Chapter 3 --- Analysis Methods --- p.29 / Experimental Section --- p.29 / Chapter 3.1 --- Interference Lithography --- p.29 / Chapter 3.2 --- Gold grating fabrication --- p.32 / Chapter 3.2.1 --- Substrate preparation --- p.33 / Chapter 3.2.2 --- Photoresist preparation --- p.34 / Chapter 3.2.3 --- Spin coating of omnicoat and photoresist --- p.35 / Chapter 3.2.4 --- Interference lithography set-up and procedures --- p.35 / Chapter 3.2.5 --- The post-exposed treatments --- p.37 / Chapter 3.2.6 --- The optimal exposure time calibration --- p.37 / Chapter 3.2.7 --- Gold thin film deposition --- p.39 / Chapter 3.2.8 --- Typical gold grating sample --- p.41 / Chapter 3.3 --- Measurement system --- p.41 / Chapter 3.3.1 --- The angle dependent reflectivity measurement --- p.42 / Chapter 3.3.2 --- Data presentation of a typical band structure --- p.45 / Chapter 3.3.3 --- Periodicity measurement of the grating samples --- p.48 / Chapter 3.3.4 --- Diffracted intensity measurement of gratings --- p.52 / Chapter 3.3.5 --- Data presentation of the angle dependent diffracted intensity measurement --- p.53 / Calculation Section --- p.54 / Chapter 3.4 --- RCWA simulations --- p.54 / Chapter 3.4.1 --- The dispersion relation --- p.56 / Chapter 3.4.2 --- The diffracted intensity --- p.56 / Chapter 3.4.3 --- The field pattern graphs --- p.57 / Chapter 4 --- Resonance modes in one-dimensional gold gratings --- p.60 / Chapter 4.1 --- Structure of the gold grating samples --- p.61 / Chapter 4.2 --- Results of angle dependent reflectivity --- p.63 / Chapter 4.2.1 --- Surface Plasmon Polaritons (SPPs) --- p.65 / Chapter 4.2.2 --- Wood´ةs anomaly --- p.65 / Chapter 4.2.3 --- Waveguide Resonance (WG) --- p.67 / Chapter 4.2.4 --- Coupling of SPPs and WG --- p.67 / Chapter 4.3 --- Results of angle dependent diffracted intensity measurement --- p.68 / Chapter 4.4 --- Basic properties of SPPs and WG modes by RCWA --- p.73 / Chapter 4.4.1 --- Sample 1 (D = 40 nm) --- p.74 / Chapter 4.4.1(a) --- λ = 980 nm of Sample 1 --- p.75 / Chapter 4.4.1(b) --- λ = 633 nm of Sample 1 --- p.81 / Chapter 4.4.2 --- Sample 2 (D = 390 nm) --- p.83 / Chapter 4.4.2(a) --- λ = 980 nm of Sample 2 --- p.85 / Chapter 4.4.2(b) --- λ = 725 nm of Sample 2 --- p.87 / Chapter 4.4.2(c) --- λ = 633 nm of Sample 2 --- p.92 / Chapter 4.5 --- Summary --- p.97 / Chapter 5 --- Conclusions --- p.99 / Bibliography --- p.101

Sham, Chun Hong = 金屬光栅光學特性的實驗和理論研究 / 沈鎮康. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 109-111). / Abstract also in Chinese. / Sham, Chun Hong = Jin shu guang shan guang xue te xing de shi yan he li lun yan jiu / Shen Zhenkang. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Overview of the Thesis --- p.2 / Chapter 2 --- Basic Theory --- p.4 / Chapter 2.1 --- Dielectric Constant of Metals --- p.5 / Chapter 2.2 --- The Maxwell´ةs Equations --- p.7 / Chapter 2.3 --- Scaling Properties of the Maxwell´ةs Equations --- p.9 / Chapter 2.4 --- Translational Symmetry and the Bloch´ةs Theorem --- p.10 / Chapter 2.4.1 --- Continuous Translational Symmetry --- p.11 / Chapter 2.4.2 --- Discrete Translational Symmetry --- p.12 / Chapter 2.4.3 --- Photonic Bloch´ةs Theorem --- p.13 / Chapter 3 --- Principles of Rigorous Coupled Wave Analysis --- p.14 / Chapter 3.1 --- Mathematical Formulation --- p.15 / Chapter 3.2 --- One-layer systems --- p.15 / Chapter 3.3 --- Layered Systems --- p.19 / Chapter 3.3.1 --- Matching Boundary Conditions --- p.19 / Chapter 3.3.2 --- The Transfer Matrices --- p.21 / Chapter 3.3.3 --- Scattering Matrices --- p.22 / Chapter 3.4 --- Calculation of Reflection and Transmission --- p.24 / Chapter 3.5 --- Calculation of Field Pattern --- p.26 / Chapter 3.5.1 --- Finding the Coefficients --- p.26 / Chapter 3.5.2 --- Summing to Get the Field --- p.27 / Chapter 3.6 --- 5-polarization --- p.27 / Chapter 3.7 --- Analogy to mechanics --- p.29 / Chapter 3.8 --- Conclusion --- p.30 / Chapter 4 --- Numerical Implementation of Rigorous Coupled Wave Analysis --- p.31 / Chapter 4.1 --- Finite Number of Terms --- p.31 / Chapter 4.2 --- Fourier Factorization Rule --- p.32 / Chapter 4.3 --- Calculation of Field Pattern --- p.34 / Chapter 4.4 --- Transfer Matrix for Forward Deduction --- p.36 / Chapter 4.5 --- Calculation of Time-Averaged Poynting Vector --- p.36 / Chapter 4.6 --- Convergence of RCWA --- p.37 / Chapter 4.7 --- Simple Examples --- p.40 / Chapter 4.7.1 --- Oblique Incidence on Vacuum --- p.40 / Chapter 4.7.2 --- Oblique Incidence on Semi-Infinite Glass --- p.41 / Chapter 4.7.3 --- Normal Incidence on a Thin Gold Film --- p.41 / Chapter 5 --- A Tunable All-Direction Light Absorber --- p.43 / Chapter 5.1 --- Description of the Absorber --- p.44 / Chapter 5.2 --- Tunability --- p.45 / Chapter 5.3 --- Theoretical Understanding on the Results --- p.46 / Chapter 5.4 --- Other EM modes Involved --- p.49 / Chapter 5.5 --- Structural Flexibility --- p.54 / Chapter 6 --- Sample Preparation Techniques --- p.57 / Chapter 6.1 --- Interference Lithography --- p.57 / Chapter 6.1.1 --- Basic Principle of IL --- p.58 / Chapter 6.1.2 --- Experimental Setup for IL --- p.59 / Chapter 6.1.3 --- Experimental Procedures for IL --- p.60 / Chapter 6.1.4 --- Tuning the Period --- p.61 / Chapter 6.1.5 --- Tuning Grating Width --- p.62 / Chapter 6.1.6 --- Tuning the grating height --- p.64 / Chapter 6.2 --- Sputtering --- p.65 / Chapter 6.2.1 --- Description of Sputtering System --- p.65 / Chapter 6.2.2 --- Effect of Varying the Position on Sample Holder --- p.66 / Chapter 6.3 --- Chemical deposition of silver --- p.69 / Chapter 7 --- Sample Characterization Techniques --- p.72 / Chapter 7.1 --- Scanning Electron Microscope --- p.72 / Chapter 7.1.1 --- Grating width measurement --- p.72 / Chapter 7.1.2 --- Sidewall Coverage Measurement --- p.73 / Chapter 7.2 --- Thickness Measurement --- p.74 / Chapter 7.3 --- Reflectance Measurement --- p.75 / Chapter 7.3.1 --- Experimental Setup --- p.76 / Chapter 7.3.2 --- Use of Prism --- p.79 / Chapter 8 --- Experimental Realization of All-Direction Light Absorber --- p.82 / Chapter 8.1 --- Reflectance of Glass Substrate --- p.82 / Chapter 8.2 --- Planar Metal-SU8-Metal Systems --- p.87 / Chapter 8.3 --- SU8 Grating on Glass Substrate --- p.89 / Chapter 8.4 --- SU8 Grating on Gold Substrate --- p.92 / Chapter 8.4.1 --- Grating on a Thick Layer of Gold --- p.93 / Chapter 8.4.2 --- Grating on a Thin Layer of Gold --- p.93 / Chapter 8.5 --- Cavities-Embedded Systems and Future Work --- p.96 / Chapter 8.6 --- Summary and Future Experimental Work --- p.100 / Chapter 9 --- Conclusion --- p.102 / Chapter A --- Notes on Glass Cleaning --- p.104 / Chapter B --- An Experiment on Sidewall Coverage --- p.107 / Bibliography --- p.109

Xiao, Manda = 金納米晶修飾的空心介孔二氧化矽微球在表面等離子體激元調製下的光散射行為 / 肖蔓達. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Abstracts in English and Chinese. / Xiao, Manda = Jin na mi jing xiu shi de kong xin jie kong er yang hua xi wei qiu zai biao mian deng li zi ti ji yuan diao zhi xia de guang san she xing wei / Xiao Manda. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgement --- p.iv / Table of Contents --- p.vi / List of Figures --- p.viii / List of Tables --- p.x / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Plasmonic Properties of Noble Metal Nanocrystals --- p.1 / Chapter 1.2 --- Light Scattering from Dielectric Spheres --- p.6 / Chapter 1.3 --- Motivations and Outline of the Thesis --- p.9 / Chapter 2 --- Characterization Techniques --- p.17 / Chapter 2.1 --- Instrumentation --- p.17 / Chapter 2.2 --- Extinction Measurement of Au Nanocrystals and the HMSMSs Decorated with the Au Nanocrystals --- p.17 / Chapter 2.3 --- Sample Preparation for the TEM and SEM Characterization --- p.18 / Chapter 2.4 --- Dark-Field Imaging and Spectroscopy of the Individual Microspheres --- p.19 / Chapter 3 --- Fabrication of Hollow Mesoporous Silica Microspheres Decorated with the Au Nanocrystals --- p.25 / Chapter 3.1 --- Preparation of the Hollow Mesoporous Silica Microspheres --- p.25 / Chapter 3.2 --- Growth of the Au Nanocrystals --- p.29 / Chapter 3.3 --- Assembly of the Au Nanocrystals onto the Hollow Mesoporous Silica Microspheres --- p.32 / Chapter 4 --- Resonant Scattering Properties of the Hollow Mesoporous Silica Microspheres --- p.38 / Chapter 4.1 --- Experimental Results --- p.38 / Chapter 4.2 --- Calculation of the Scattering Spectra by Mie Theory --- p.42 / Chapter 4.3 --- Summary --- p.46 / Chapter 5 --- Resonant Scattering Properties of the Au Nanocrystal-Decorated Hollow Mesoporous Silica Microspheres --- p.49 / Chapter 5.1 --- Effect of the Plasmon Resonances of the Au Nanocrystals on the Resonant Scattering Behaviors of the HMSMSs --- p.49 / Chapter 5.2 --- Estimation of the Scattering Enhancement Factors --- p.54 / Chapter 5.3 --- Summary --- p.59 / Chapter 6 --- Summary --- p.61

Graduation date: 1998

Graduation date: 1995

Molecular optical imaging enables the ability to non-invasively image biological function. When used in conjunction with optical contrast agents, molecular imaging can provide biomarker-specific information with subcellular spatial resolution. Plasmonic nanoparticles are unique optical contrast agents due to the fact that the intensity and peak wavelength of scattering is dependant on interparticle spacing. This distance dependance puts these nanosensors in a position to probe molecular interactions by exploiting contrast between isolated and closely spaced nanoparticles. This dissertation presents the first intracellular molecular imaging platform using multifunctional gold nanoparticles which incorporate both cytosolic delivery and targeting moieties on the same particle. In order to produce robust nanosensors, a novel conjugation strategy was developed involving a heterofunctional linker capable of rigidly attaching various components to the nanoparticle surface. Since most biomarkers of interest are localized intracellularly, the delivery functionality was a key focus. It was achieved using the TAT-HA2 fusion peptide which has been previously shown to enhance both endosomal uptake and subsequent release into the cytosol. The feasibility of these nanoparticles as intracellular sensors was proposed by attempting to image actin rearrangement in live fibroblasts. The assembly of nanoparticles at the leading of motile cells was which was potentially due to actin targeting resulted in a red shift in scattering maxima due to plasmon resonance coupling between particles as well as a dramatic increase in scattering intensity. Although several challenges still exist, the potential for these contrast agents as nanosensors for the presence of proteins implicated in viral carcinogenesis is also introduced. / text

In this thesis, Gallium Nitride (GaN) micro- and nanostructures were fabricated based on focused ion beam (FIB) milling. The starting wafer is an epitaxial structure containing InGaN/GaN multi-quantum wells. High crystal quality structures such as the nano-cone, nanopillar array and single pillar were fabricated based on the FIB method. During the fabrication process, various approaches were designed to minimize FIB damage caused by Gallium ion bombardment. The fabrication process for nano-cone is a combination of mask preparation by FIB with subsequent reactive ion etching (RIE). For fabricating nanopillar arrays, the nanopillars were patterned directly using FIB with an optimized beam current followed by wet etching process to remove the damage. On the other hand, the single pillar is achieved by gradually decreasing the ion beam current as the diameter of the pillar becomes smaller. The first order Raman spectra for the nanopillar array reveal a strong additional peak when the diameter of the nanopillars is less than 220 nm. This peak can also be observed in GaN pillars without MQW and is clearly assigned to the surface optical (SO) mode originated from the A1 phonon in wurtzite GaN. The frequency of this SO mode is found to be sensitive with the diameter and surface roughness of the nanopillars. Temperature-variable photoluminescence (PL) measurements show that a broadband emission in the as-grown sample split into the two well-resolved bands for nanopillars and the emission band at the higher energy side quickly thermally quenched. Room temperature PL measurements on the single pillars exhibit an increasing blue-shift of the peak emission with the decreasing of the pillar diameter. Additional simulation data and excitation power dependent PL studies confirm the observation of strain relaxation in the pillar’s MQW due to FIB fabrication. The temperature variable PL on the single pillar shows a monotonous blue shift as the temperature arises to 300 K. / published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

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