• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 376
  • 97
  • 72
  • 48
  • 22
  • 16
  • 7
  • 6
  • 5
  • 5
  • 4
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 772
  • 772
  • 220
  • 127
  • 112
  • 105
  • 103
  • 99
  • 98
  • 97
  • 90
  • 90
  • 86
  • 74
  • 73
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Fluctuational electrodynamics for nonlinear materials in and out of equilibrium

Soo, Heino 16 April 2019 (has links)
No description available.
172

Spectroscopic studies of hyper-rayleigh scattering from organic liquids. / 由有機物質發放的超瑞利散射的光譜性硏究 / Spectroscopic studies of hyper-rayleigh scattering from organic liquids. / You you ji wu zhi fa fang de chao rui li san she de guang pu xing yan jiu

January 2000 (has links)
by Cheung Ka Wing = 由有機物質發放的超瑞利散射的光譜性硏究 / 張家榮. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 94-95). / Text in English; abstracts in English and Chinese. / by Cheung Ka Wing = You you ji wu zhi fa fang de chao rui li san she de guang pu xing yan jiu / Zhang Jiarong. / Title Page --- p.i / Acknowledgments --- p.ii / Abstract --- p.iii / Chinese Abstract --- p.iv / Table of Contents --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Nonlinear Optics --- p.1 / Chapter 1.2 --- Tensor Properties of the Polarizability --- p.4 / Chapter 1.3 --- Inversion Symmetry --- p.5 / Chapter 1.4 --- Second Harmonic Generation --- p.6 / Chapter 1.5 --- Outline --- p.10 / Chapter Chapter 2 --- Measurement of the First Hyperpolarizability β --- p.11 / Chapter 2.1 --- Scattering by a Single Small Particle --- p.11 / Chapter 2.2 --- Rayleigh Scattering --- p.13 / Chapter 2.3 --- Fluctuation --- p.15 / Chapter 2.4 --- Hyper-Rayleigh Scattering --- p.16 / Chapter 2.5 --- Coherent and Incoherent Optical Processes --- p.16 / Chapter 2.6 --- Difference between Second Harmonic Generation (SHG) and Hyper Rayleigh Scattering (HRS) --- p.17 / Chapter 2.7 --- Measurement of the First Hyperpolarizability β by Electric Field Induced Second harmonic Generation (EFISHG) --- p.20 / Chapter 2.8 --- Measurement of the First Hyperpolarizability β by Hyper-Rayleigh Scattering (HRS) --- p.22 / Chapter 2.9 --- Two-Component System ´ؤ´ؤInternal Reference Method (IRM) and External Reference Method (ERM) --- p.23 / Chapter 2.10 --- Orientation Average of β --- p.25 / Chapter Chapter 3 --- Experimental Setup --- p.29 / Chapter 3.1 --- Detail Description of the Main Components --- p.29 / Chapter A). --- Laser System --- p.29 / Chapter B). --- Monochromator --- p.33 / Chapter C). --- Photomultiplier Tubes (PMT) --- p.36 / Chapter D). --- Photon Counter --- p.37 / Chapter 3.2 --- Layout of the Optical Design and Alignment Procedures --- p.39 / Chapter 3.3 --- Difficulties in the Experiment --- p.42 / Chapter A). --- Alignment --- p.42 / Chapter B). --- Temporal Stability of the Apparatus --- p.43 / Chapter C). --- The Effects of Using Different Sample Cells --- p.47 / Chapter 3.4 --- Sample Preparation --- p.48 / Chapter 3.5 --- Special Interest on the Organic Compounds --- p.49 / Chapter Chapter 4 --- Measurement on p-nitroaniline --- p.52 / Chapter 4.1 --- The Spectrum of Light Signal from pNA --- p.52 / Chapter 4.2 --- Concentration Dependence Measurement --- p.54 / Chapter Chapter 5 --- Measurement of the Hyperpolarizability of a Fluorescence Dye --- p.58 / Chapter 5.1 --- The Spectrum of Light Signal from DANS --- p.58 / Chapter 5.2 --- Design of an Experimental Technique to Measure β of Fluorescence Dyes that is Absorptive at the Second Harmonic --- p.61 / Chapter 5.3 --- Result of the Measurement on DANS --- p.64 / Chapter Chapter 6 --- Studies of the First Hyperpolarizability β of Two New Compounds --- p.74 / Chapter 6.1 --- The New Compounds --- p.74 / Chapter 6.2 --- Measurement on NC1 --- p.75 / Chapter 6.3 --- Measurement on NC2 --- p.79 / Chapter Chapter 7 --- Probing the Molecular Interaction in a Liquid Using HRS --- p.84 / Chapter 7.1 --- The Spectrum of Light Signal from Nitrobenzene --- p.85 / Chapter 7.2 --- The Signal Depolarization Ratio --- p.86 / Chapter 7.3 --- Results of the Depolarization Ratio Measurement on pNA --- p.87 / Chapter 7.4 --- Results of the Depolarization Ratio Measurement on Nitrobenzene --- p.88 / Chapter Chapter 8 --- Conclusions --- p.91 / References --- p.94
173

Nonlinear silicon waveguides for integrated fiber laser systems. / CUHK electronic theses & dissertations collection

January 2013 (has links)
Wong, Chi Yan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 134-149). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
174

Poling dynamics of nonlinear optical guest-host polymer systems. / 具非線性光學性質客體-主體聚合物系統的極化動力學研究 / Poling dynamics of nonlinear optical guest-host polymer systems. / Ju fei xian xing guang xue xing zhi ke ti-zhu ti ju he wu xi tong de ji hua dong li xue yan jiu

January 2006 (has links)
To Chi Wing = 具非線性光學性質客體-主體聚合物系統的極化動力學研究 / 杜志榮. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 102-104). / Text in English; abstracts in English and Chinese. / by To Chi Wing = Ju fei xian xing guang xue xing zhi ke ti-zhu ti ju he wu xi tong de ji hua dong li xue yan jiu / Du Zhirong. / Table of contents / Acknowledgements --- p.ii / Abstract --- p.iii / Chinese Abstract --- p.iv / Table of Contents --- p.v / List of Figures --- p.viii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Fundamental of nonlinear optics --- p.2 / Chapter 1.2 --- Centrosymmetry and even-order nonlinear susceptibilities --- p.4 / Chapter 1.3 --- Generation of second harmonic radiation --- p.5 / Chapter 1.4 --- Tensor properties of the nonlinear susceptibilities --- p.7 / Chapter 1.5 --- Relationship between macroscopic and microscopic nonlinear susceptibility for a poled polymer --- p.8 / Chapter 1.6 --- Outline of the thesis --- p.12 / Figures --- p.13 / Chapter Chapter 2 --- Poling and Relaxation of Guest-host Polymeric System --- p.15 / Chapter 2.1 --- Guest-host nonlinear optical polymeric systems --- p.15 / Chapter 2.1.1 --- Photoisomerization of Azobenzene --- p.16 / Chapter 2.1.2 --- Disperse Red-1 --- p.17 / Chapter 2.1.3 --- Poly (methyl methacrylate) --- p.18 / Chapter 2.2 --- Poling techniques --- p.19 / Chapter 2.2.1 --- Thermal Assisted Electric-field Poling --- p.19 / Chapter 2.2.2 --- Photo-assisted Electric-field poling --- p.22 / Chapter 2.2.3 --- All-Optical Poling --- p.25 / Chapter 2.3 --- Relaxation of poled nonlinear optical polymers --- p.27 / Figures --- p.31 / Chapter Chapter 3 --- Experimental Methods --- p.36 / Chapter 3.1 --- Sample Preparation --- p.36 / Chapter 3.2 --- Experimental Setup --- p.38 / Chapter 3.2.1 --- Laser system --- p.38 / Chapter 3.2.2 --- The reference arm --- p.39 / Chapter 3.2.3 --- The sample arm --- p.40 / Chapter 3.2.4 --- Data acquisition (DAQ) system --- p.41 / Chapter 3.2.5 --- Temperature control --- p.42 / Chapter 3.3 --- Poling and the erasing of thermal history --- p.43 / Chapter 3.3.1 --- All Optical Poling --- p.43 / Chapter 3.3.2 --- Eecteic Poling --- p.44 / Chapter 3.3.3 --- Erasure of thermal history --- p.45 / Figures --- p.46 / Chapter Chapter 4 --- Experimental results and discussions --- p.51 / Chapter 4.1 --- Reliability and reproducibility --- p.51 / Chapter 4.2 --- Features of different poling techniques --- p.52 / Chapter 4.2.1 --- Sub-Tg electric Poling --- p.53 / Chapter 4.2.2 --- Thermal assisted electric Poling --- p.54 / Chapter 4.2.3 --- Photo assisted electric Poling --- p.55 / Chapter 4.3 --- Relaxation of poling induced x(2) --- p.56 / Chapter 4.4 --- Effect of physical aging on the relaxation of PAP induced x{2) --- p.58 / Chapter 4.4.1 --- Origin of physical aging and its effect on relaxation --- p.58 / Chapter 4.4.2 --- Effect of aging on the relaxation of a PAP sample --- p.59 / Chapter 4.5 --- Onset studies of photo-induced free volume --- p.61 / Chapter 4.6 --- Comparative studies of TAP and PAP induced x{2) --- p.62 / Chapter 4.6.1 --- Secondary Poling --- p.63 / Chapter 4.6.1.1 --- Model for describing the temporal behavior of secondary poling --- p.65 / Chapter 4.6.1.2 --- Experimental details of the secondary poling measurement --- p.68 / Chapter 4.6.1.3 --- Results and Discussion on secondary poling of sample poled by TAP or PAP --- p.69 / Chapter 4.6.2 --- Onset of second harmonic signal during electric poling --- p.71 / Chapter 4.7 --- Charge injection studies --- p.73 / Figures --- p.77 / Chapter Chapter 5 --- Conclusion --- p.98 / References --- p.101
175

New approaches for laser pulse generation and signal processing using optical phase modulation.

January 2003 (has links)
Chan Sze-wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.vi / Table of contents --- p.vii / List of figure --- p.xi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Optical non-linearity of fiber and semiconductor optical amplifier (SOA) --- p.2 / Chapter 1.2. --- Applications on optical non-linearity --- p.3 / Chapter 1.2.1. --- Wavelength tunable pulse generation --- p.3 / Chapter 1.2.2. --- Wavelength conversion --- p.5 / Chapter 1.2.3. --- All-optical NRZ to RZ format conversion --- p.7 / Chapter 1.2.4. --- All-optical pulse compression and reshaping --- p.9 / Chapter 1.3. --- Overview --- p.11 / Reference --- p.13 / Chapter 2. --- Principles and Theories --- p.16 / Chapter 2.1. --- Optical non-linearity --- p.17 / Chapter 2.1.1. --- Self-phase modulation (SPM) --- p.19 / Chapter 2.1.2. --- Cross-phase modulation (XPM) --- p.22 / Chapter 2.2. --- Principle of dispersion tuning --- p.25 / Chapter 2.2.1. --- Nonlinear optical loop mirror (NOLM) incorporated with SOA --- p.29 / Chapter 2.2.2. --- Principle of compensated dispersion tuning in harmonically mode-locked fiber ring --- p.33 / Chapter 2.3 --- Principle of double-pass dispersion-shifted fiber (DSF) based on SPM --- p.36 / Reference --- p.38 / Chapter 3. --- Preliminary experimental studies on spectral broadeningin SOAs and DSF by XPM --- p.39 / Chapter 3.1. --- XPM in SOA --- p.40 / Chapter 3.2. --- XPM in DSF --- p.44 / Chapter 3.3. --- Comparison in XPM performance between SOA and DSF --- p.47 / Chapter 4. --- Harmonically mode-locked fiber laser with an optically selectable wavelength --- p.48 / Chapter 4.1. --- Introduction to wavelength tunable pulse generation and basic idea --- p.49 / Chapter 4.2. --- Experimental details --- p.51 / Chapter 4.3. --- Results and discussions --- p.55 / Chapter 4.4. --- Conclusion --- p.61 / Reference --- p.62 / Chapter 5. --- Spectral broadening by XPM in DSF for wavelength conversion --- p.64 / Chapter 5.1. --- Overview of wavelength conversion --- p.65 / Chapter 5.2. --- Description of experimental setup --- p.67 / Chapter 5.3. --- Optical spectral analysis and eye patterns --- p.69 / Chapter 5.4. --- Data Analysis --- p.72 / Chapter 5.5. --- Conclusion --- p.75 / Reference --- p.76 / Chapter 6. --- Spectral filtering from a cross-phase modulated signal for all- optical NRZ to RZ format conversion --- p.77 / Chapter 6.1. --- Importance of format conversion --- p.78 / Chapter 6.2. --- Principle and explanation of experimental setup --- p.79 / Chapter 6.3. --- Experimental results and bit error rate test --- p.81 / Chapter 6.4. --- Conclusion --- p.87 / Reference --- p.88 / Chapter 7. --- Spectral filtering from a cross-phase modulated signal for all- optical pulse compression and reshaping in a DSF --- p.90 / Chapter 7.1. --- Pulse compression by XPM / Chapter 7.1.1. --- Introduction --- p.91 / Chapter 7.1.2. --- Details of experimental setup --- p.93 / Chapter 7.1.3. --- Experimental results / Chapter 7.1.3.1. --- Output spectra and eye patterns --- p.95 / Chapter 7.1.3.2. --- Data analysis and discussions --- p.97 / Chapter 7.2. --- Pulse restoration by XPM / Chapter 7.2.1. --- Details of experiment --- p.99 / Chapter 7.2.2. --- Output eye patterns --- p.101 / Chapter 7.3. --- Conclusion for pulse compression and reshaping by XPM --- p.102 / Reference --- p.103 / Chapter 8. --- Spectral filtering from a self-phase modulated signal with double-pass DSF for all-optical pulse compression and reshaping --- p.104 / Chapter 8.1. --- Introduction to pulse compression by SPM and basic idea of double-pass DSF --- p.105 / Chapter 8.2. --- Schematic diagram of experimental setup --- p.107 / Chapter 8.3. --- Experimental Results and discussions / Chapter 8.3.1. --- Results measured by optical spectrum analyzer and oscilloscope --- p.109 / Chapter 8.3.2. --- Data comparison with conventional SPM and bit-error rate test --- p.113 / Chapter 8.4. --- Conclusion --- p.117 / Reference --- p.118 / Chapter 9. --- Conclusion and future works / Chapter 9.1. --- Conclusion --- p.119 / Chapter 9.2. --- Possible future works --- p.122 / Appendix / List of publications --- p.A-l
176

Studies of nonlinear light scattering in organic liquids and metal colloids. / 由有機液體以及金屬膠體產生的非線性光散射的研究 / CUHK electronic theses & dissertations collection / Studies of nonlinear light scattering in organic liquids and metal colloids. / You you ji ye ti yi ji jin shu jiao ti chan sheng de fei xian xing guang san she de yan jiu

January 2009 (has links)
In our research Hyper-Rayleigh scattering (HRS) is employed as an effective, simple investigation technique to study solutions of small molecules, pure liquids, nano-adsorbing systems and metal colloids. A set of apparatus has been built with good spectral resolution and high sensitivity to successfully measure characteristics of intensity and polarization properties of HRS. It was found that the consistency was different for pure liquid and solutions of small molecules when comparing experimental measurements of depolarized ratios and polarization patterns with theoretical expectations. This is due to the presence of both incoherent and coherent contributions to HRS in pure liquids, of which the origin of the coherent contribution is different for different pure liquids. In our results, pure liquid nitrobenzene was found to have strong coherent contribution to HRS caused by intermolecular interactions. Three different chemical compounds were used to mix with nitrobenzene to break the strong orientational correlations between molecules. Comparison between the results show different behaviors in the effectiveness in eliminating the coherent HRS signals, and the effectiveness was correlated to the molecular structures. Theory of second harmonic scattering from surface has been expanded as leading order contributions containing nonlocal electric dipole mode and local quadrupole mode, which can be exhibited in our experimental study of polarization patterns. Polarization patterns from polystyrene particles of different sizes adsorbed with different species of dyes were measured to investigate and compare with theoretical expectations. For small-size adsorbing system, measurements of polarization patterns were basically consistent with theory. However, for adsorbing system of polystyrene particles with a size of 900 nm, the polarization patterns showed discrepancies when comparing with theory, which indicated that higher order multipoles are needed in the theory. Silver and gold colloids were employed as the subject of investigation for measuring the polarization patterns of HRS. The results were found to be consistent when comparing with their extinction spectra and TEM images. We have managed to measure polarization patterns of HRS originated from surface of non-spherical colloids and the results showed that the origin of HRS can be qualitatively understood, although a more elaborated theory is needed to describe the data. / by Chen, Ji = 由有機液體以及金屬膠體產生的非線性光散射的研究 / 陳佶. / Source: Dissertation Abstracts International, Volume: 70-09, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 117-118). / 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. / by Chen, Ji = You you ji ye ti yi ji jin shu jiao ti chan sheng de fei xian xing guang san she de yan jiu / Chen Ji.
177

Study of hyper-rayleigh scattering in organic liquids =: 利用超瑞利散射方法探討有機質之硏究. / 利用超瑞利散射方法探討有機質之硏究 / Study of hyper-rayleigh scattering in organic liquids =: Li yong chao rui li san she fang fa tan tao you ji zhi zhi yan jiu. / Li yong chao rui li san she fang fa tan tao you ji zhi zhi yan jiu

January 1998 (has links)
by T.W. Chui. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 79-81). / Text in English; abstract also in Chinese. / by T.W. Chui. / Titleage --- p.i / Acknowledgments --- p.ii / Abstract --- p.iii / Table of contents --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Figure Captions --- p.16 / Chapter Chapter 2 --- Meauserment of first hyperpolarizability / Chapter 2.1 --- Electric Field Induced Second Hamonics (EFISH) --- p.21 / Chapter 2.2 --- Hyper-Rayleigh Scattering (HRS) --- p.23 / Chapter 2.3 --- Internal reference method and External reference method --- p.26 / Figure Captions --- p.28 / Chapter Chapter 3 --- Experimental Setup / Chapter 3.1 --- Design of experimental setup --- p.30 / Chapter 3.2 --- Alignment --- p.32 / Chapter 3.3 --- ower --- p.33 / Chapter 3.4 --- Samples --- p.33 / Figure Captions --- p.35 / Chapter Chapter 4 --- Measurement of first hyperpolarizability of selected molecules / Chapter 4.0 --- Introduction --- p.40 / Chapter 4.1 --- Result of spectral study of the scattered signal from CV --- p.43 / Chapter 4.2 --- Result of the first hyperpolarizability of CV --- p.46 / Chapter 4.3 --- HRS measurement with DANS --- p.47 / Figure Captions --- p.51 / Graphs --- p.52 / Tables --- p.57 / Chapter Chapter 5 --- Studies of the depolarization ratio of HRS and fluorescence light from CV / Chapter 5.0 --- Introduction --- p.59 / Chapter 5.1 --- Experimental setup for the measurement of depolarization ratio --- p.60 / Chapter 5.2 --- Measurement of depolarization ratio forNA at 532nm --- p.61 / Chapter 5.3 --- Measurement of depolarization ratio for CV at 532nm --- p.62 / Chapter 5.4 --- Measurement of depolarization ratio for fluorescence light from CV --- p.63 / Figure Captions --- p.68 / Graphs --- p.71 / Tables --- p.75 / Chapter Chapter 6 --- Conclusions --- p.77 / References --- p.79
178

Terahertz nonlinear optical response of armchair graphene nanoribbons

Wang, Yichao 01 August 2016 (has links)
It has become increasingly apparent that the future of next generation of electronic devices can and will rely on graphene nanoribbons. Graphene nanoribbons and sister structures showcase several key properties that can address the emerging need of terahertz science and technology, and break through the many technological limits on conventional semiconductor electronics operating in the terahertz spectrum. In this thesis, we focus on the study of the terahertz nonlinear optical response of metallic armchair graphene nanoribbons and sister structures using a k.p model and time dependent perturbation theory. We find that these nanoribbons exhibit a stronger interband optical response, and a smaller critical field strength (of the order of 10 kV/m) than does 2D single layer graphene. We demonstrate that finite ribbon size, spatial profile of the applied terahertz radiation field, polarization of the applied terahertz radiation, a small band gap opening, and application of a superlattice potential are several ways to tune the strong terahertz nonlinear optical response of metallic armchair graphene nanoribbons. The major contributions of this thesis include: 1) developes of a simpler method compared to other sophisticated methods of the terahertz nonlinear optical interband response of metallic armchair graphene nanoribbons; 2) extends the method in the characterization of various quantum size effects, elliptically polarized radiation field, small gap opening and superlattice on the terahertz optical response of these nanoribbons; 3) The versatility of the tunability showed in the terahertz nonlinear response of metallic armchair nanoribbons and sister structures will help advance the development of the nonlinear terahertz armchair graphene nanoribbon opto-electronic and photonic technology.
179

Aspects of organometallic chemistry, particularly metal alkynyl and cluster chemistry

Humphrey, Mark Graeme. January 2002 (has links) (PDF)
Includes bibliographical references. Details research carried out into the nonlinear optical properties of metal alkynyls, chiefly organoruthenium complexes, showing that these complexes can be designed to have very large NLO coefficients. Also demonstrates the utility of spectroscopic, electrochemical and copmutational aids as predictive tools for NLO materials. Also examines cluster synthesis, reactivity and physical properties using ruthenium clusters and hard-donor ligands, affording a series of cluster complrxes that provide structural models for industrially-important hydrotreating intermediates.
180

Aspects of organometallic chemistry, particularly metal alkynyl and cluster chemistry / by Mark Graeme Humphrey.

Humphrey, Mark Graeme. January 2002 (has links)
Includes bibliographical references. / 3 v. : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Details research carried out into the nonlinear optical properties of metal alkynyls, chiefly organoruthenium complexes, showing that these complexes can be designed to have very large NLO coefficients. Also demonstrates the utility of spectroscopic, electrochemical and copmutational aids as predictive tools for NLO materials. Also examines cluster synthesis, reactivity and physical properties using ruthenium clusters and hard-donor ligands, affording a series of cluster complrxes that provide structural models for industrially-important hydrotreating intermediates. / Thesis (D.Sc.)--University of Adelaide, Dept. of Chemistry, 2003

Page generated in 0.0818 seconds