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

Thesis--University of Oklahoma. / Photocopy of typescript, Ann Arbor, MI. : University Microfilms, 1978. -- 21 cm. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 232-241).

Magnetic properties are becoming increasingly important, especially with the advent of new technologies such as data storage, spintronics, and magnetic random access memory (MRAM). These technologies all benefit from the ability to characterize and optimize magnetic materials, which can be accomplished through the implementation of the magneto-optical Kerr effect (MOKE). This probing technique is described in detail along with the results of a self-built, longitudinal MOKE (L-MOKE) experiment that is used to determine the Kerr angle and ellipticity for the Heusler compound Fe2MnSn. The results from L-MOKE are combined with raw X-ray Diffraction (XRD) data in order to develop a complete picture of the material by connecting the Kerr response with the crystal structure. Trends in the crystal structure and magnetic properties of Fe2MnSn are developed and analyzed in order to isolate crystallographic directions that are primarily responsible for unique magnetic properties such as perpendicular magnetic anisotropy. Complementary techniques are also introduced to further the capabilities from a single geometry MOKE experiment to a compound experiment using all three geometries of MOKE with the ability to probe micro-structures, determine magneto-optical parameters, and create magnetic domain images.

Three applications of Smith's model of magneto-optical effects in stratified magnetic media are presented. Each application involves the incident-angle dependence of magneto-optical effects which Smith's model treats explicitly. In addition. the three applications address current issues in magnetic and magneto-optical recording. The first problem considered is that of nonmagnetic surface layers which form on magnetic recording heads. The second is a theoretical treatment of effects which arise in magneto-optical recording when high numerical-aperture optical systems are combined with media exhibiting interference-enhanced optical properties. The final application is a novel technique for determining the entire dielectric tensor of materials used for magneto-optical recording. The incident-angle dependence of the longitudinal Kerr effect is employed to study nonmagnetic surface layers which form on ferrite recording heads. Calculations based on the Smith model show a correlation between the inert-layer thickness and the incident-angle dependence of the longitudinal Kerr effect. Experimental results confirm the shift in the angular position of the signal peak. in agreement with the theory for finite inert-layer thickness. An unambiguous determination of the inert-layer thickness for ferrite materials is prevented because of a periodic dependence of the peak angle on the inert-layer thickness. Jones-matrix algebra is used with the Smith model to quantitatively determine the effects of obliquely-incident rays on the reflectance and magneto-optical readout signals for various magneto-optical media structures. The most antireflective structure is found to be very sensitive to incident-angle effects. Structures with moderate reflectance (>10%). however. are not significantly affected by incident-angle effects. Finally. a technique for the determination of the optical and magneto-optical constants from multiple incident-angle measurements of reflectance and Kerr rotation is presented. The experimental system employs a Helium-Neon laser and a rotating differential detection system. The technique is used to investigate the optical properties of a series of Cu/Co multilayers and a comparison with a model based on the bulk optical. constants of Cu and Co is made. Anomalous behavior is observed for multilayers with very thin periods.

No description available.

Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01

In giant magnetoresistance (GMR) or tunneling magnetoresistance (TMR) materials, the transport properties rely on the related spin configurations, i.e., the parallel spin configuration in both magnetic layers is responsible for the lower resistivity state while the antiparallel spin configuration between them exhibit the higher resistivity state. However, the magnetic materials in realistic do not align completely in one direction; they exhibit magnetic domains to reduce the dipolar interaction instead. It is thus crucial to investigate in detailed about how the magnetic domain evolution influences the magnetoresistance in GMR or TMR materials. So, Photoemission Electron Microscopy (PEEM) and Kerr microscope are very good tools for us to study the magnetic domain in local area. The in-situ preparation Mn/Ag wedge/Fe(100) ultrathin films are measured by Auger electron spectroscopy (AES), low energy electron diffraction (LEED), medium energy electron diffraction (MEED), and photoemission electron microscope (PEEM) in an ultrahigh vacuum chamber. The preparation Ti/Fe/Ti/SiO2/Si(100) thin films are performed in an ultrahigh vacuum chamber and then are measured by Kerr Microscopy in air. By observing the evolution of magnetic domain, we can know more the detailed information on magnetism microscopically and the correlation between the magnetic properties and electric transport properties.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Not available / text

Mr T. J. Sono, an MSc student during the period January 2001 to January 2003, developed an apparatus to measure the pressure and temperature dependence of the electric-field induced birefringence (or electro-optic Kerr effect) in gases. Mr Sono obtained experimental results for dimethyl ether at a wavelength of 632.8 nm resulting in polarizability tensor components, first and second Kerr hyperpolarizabilities, and second Kerr-effect virial coefficients for this particular molecular species. One of the primary concerns of this thesis has been to obtain new measured Kerr-effect data for dimethyl ether and for trifluoromethane over a range of temperature. The cell has been calibrated using hydrogen as a primary standard, and has been carefully aligned to avoid multiple reflections of the incident laser beam off the closely-spaced electrode surfaces. The data has been analyzed to extract values of the polarizability anisotropy and the second Kerr hyperpolarizability for these molecules. In addition, precise values for the second Kerr-effect virial coefficients have been obtained from measurements of the Kerr effect a function of pressure. The molecular-tensor theory of the second Kerr-effect virial coefficient BK is reviewed. This theory describes the effects of intermolecular interactions on the molar Kerr constant, and it has been used to compute BK for dimethyl ether and trifluoromethane over the experimental temperature range. Agreement between experiment and theory is generally good. BK for ammonia has also been calculated, and compared to recent measured data found in the literature. The theory of the Cotton-Mouton effect (the magnetic analogue of the Kerr-effect) in a dilute gas is reviewed, and a new molecular-tensor theory describing the effects of molecular pair-interactions is developed. Calculations for a test molecule, namely chloromethane, indicate that density-dependent effects for this molecule are extremely tiny (of the order of 1% for typical experimental pressures). This new theory could be profitably used in selecting molecules which might demonstrate a larger effect which might be more readily measured in the laboratory. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.