Yung, Man Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references. / Yung, Man Fai. / Acknowledgements --- p.iii / Abstract --- p.iv / Preface --- p.vi / Contents --- p.vii / List of Figures --- p.x / List of Tables --- p.xii / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Physical Origin of Optical Nonlinearity --- p.3 / Chapter 1.1.1 --- Mathematical Description --- p.3 / Chapter 1.1.2 --- Anharmonic Oscillator Model --- p.4 / Chapter 1.2 --- Nonlinear Optical Susceptibility --- p.4 / Chapter 1.2.1 --- Molecular Hyperpolarizability --- p.4 / Chapter 1.2.2 --- Macroscopic Nonlinear Susceptibility --- p.5 / Chapter 1.2.3 --- Kleinman Conjecture --- p.6 / Chapter 1.3 --- Third-Order Nonlinear Optical Process --- p.7 / Chapter 1.3.1 --- Intensity Dependent Refractive Index --- p.7 / Chapter 1.3.2 --- Physical Mechanisms --- p.8 / Chapter 1.3.3 --- Tensor Nature of Third-Order Susceptibility x(3) --- p.10 / Chapter 1.3.4 --- Conventions for Nonlinear Susceptibility --- p.11 / References --- p.12 / Chapter Chapter 2. --- Optical Kerr Effect --- p.13 / Chapter 2.1 --- Introduction --- p.13 / Chapter 2.2 --- Theoretical Background --- p.14 / Chapter 2.2.1 --- Pump-Probe Technique --- p.14 / Chapter 2.2.2 --- Description of Induced Birefringence --- p.15 / Chapter 2.2.3 --- Signal Transmitted through OKE --- p.17 / Chapter 2.2.4 --- Resonant OKE --- p.18 / Chapter 2.2.5 --- Third-Order Autocorrelation --- p.19 / Chapter 2.3 --- Applications --- p.20 / References --- p.21 / Tables --- p.23 / Figure Captions --- p.24 / Chapter Chapter 3. --- Nonlinear Optical Properties of Fullerenes --- p.26 / Chapter 3.1 --- Introduction --- p.26 / Chapter 3.2 --- Second Harmonic Generation --- p.27 / Chapter 3.3 --- Third-Order Effects --- p.28 / Chapter 3.4 --- Reverse Saturable Absorption and Optical Limiting --- p.29 / References --- p.32 / Figure Captions --- p.34 / Chapter Chapter 4. --- Excited State Enhancement --- p.38 / Chapter 4.1 --- Introduction --- p.38 / Chapter 4.2 --- Origin and Properties of Excited State Enhancement --- p.39 / Chapter 4.3 --- Experimental Demonstrations --- p.42 / References --- p.44 / Chapter Chapter 5. --- Experimental Setup --- p.46 / Chapter 5.1 --- Introduction --- p.46 / Chapter 5.2 --- Laser System --- p.46 / Chapter 5.3 --- Optical Layout --- p.48 / Chapter 5.4 --- Sample Preparation --- p.50 / Chapter 5.5 --- Detection System --- p.51 / Chapter 5.6 --- Third-Order Autocorrelation Measurement --- p.52 / Chapter 5.7 --- Optical Limiting Measurement --- p.53 / Chapter 5.8 --- Excited State Enhancement Measurement --- p.54 / References --- p.56 / Figure Captions --- p.57 / Chapter Chapter 6. --- Results and Discussion --- p.69 / Chapter 6.1 --- Introduction --- p.69 / Chapter 6.2 --- Results of Pure Liquids --- p.69 / Chapter 6.2.1 --- Carbon Disulfide (CS2) --- p.69 / Chapter 6.2.2 --- Toluene --- p.71 / Chapter 6.2.3 --- Nitrobenzene --- p.71 / Chapter 6.3 --- Third-Order Autocorrelation of CS2 --- p.74 / Chapter 6.4 --- Results of Fullerenes C60 and C70 --- p.75 / Chapter 6.5 --- Optical Limiting of C60 --- p.78 / Chapter 6.6 --- Excited State Enhancement of Fullerenes --- p.79 / References --- p.82 / Tables --- p.85 / Figure Captions --- p.90 / Chapter Chapter 7. --- Conclusion --- p.108

Optical properties (transmission and refractive index) and chemical structure (XPS) of diamond-like coating (DLC) film before and after focused ion beam milling (FIBM) process, were investigated in this paper. It is shown by our FIBM experiment that influence of FIBM on Optical properties and chemical structure of the DLC film is not apparent, especially in near-infra region. The film still can be used for optical applications. As an application example, diffractive optical element (DOE) was directly fabricated on the film by use of FIBM. Measured diffraction efficiency of the DOE is 73%, which is acceptable for conventional use. / Singapore-MIT Alliance (SMA)

In this thesis, I present studies in the field of terahertz [THz] spectroscopy. It covers both the generation and detection of ultra-fast broadband THz pulses, as well as the transmission properties of vertically grown multi-walled carbon nanotube forests [MWCNTs]. We have found that these vertically grown MWCNTs respond strongly to THz radiation and exhibit an anisotropic optical response. The analysis done was a simplified model that is frequency-indepedent, which led to discrepancies between the theoretical and experimental data. This suggests that the response of the CNTs is frequency-dependent, and further, more complex analysis is required to fully describe their properties. / Graduation date: 2013

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

　Zinc oxide (ZnO) is a wide band gap (3.4eV at 300K) II-VI semiconductor with an exciton binding energy up to 60meV and is promising in the realization of excitonic or polaritonic lasing effect. Photoluminescence is widely used in studying the band gap and defect levels of ZnO. However, understanding in defects of ZnO is still far from satisfaction and remains controversial. Different authors suggest different explanations and mechanisms. 　In the present study we investigate in the photoluminescence spectra of four kinds of ZnO single crystal, namely as-grown (not implanted) Zn-face polished, Zn-implanted, O-implanted and He-implanted. The samples are annealed both in air and argon gas at a temperature of 350, 650, 750, 900 and 1200oC. The results show that O-implanted sample is weaker in excitonic emission and has an annealing effect tendency not consistent with that of Zn-implanted and He-implanted. Ion implantation would introduce defects in favor of yellow luminescence and the defects would anneal out gradually as the annealing temperature is rising. / published_or_final_version / Physics / Master / Master of Philosophy

Not available / text

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

No description available.

No description available.

No description available.