Showing papers on "Kerr effect published in 1998"
TL;DR: In this article, data from the optical Kerr effect, time-resolved Stokes shift, and dielectric dispersion experiments on 21 common room temperature solvents are collected and compared.
182 citations
TL;DR: In this article, strong in-plane magnetic field pulses of 2.4 ps duration are used to study magnetization reversal in perpendicularly magnetized Co/Pt films and ring domains, reminiscent of the field contour during exposure, are observed later with Kerr microscopy.
Abstract: Strong in-plane magnetic field pulses of 2--4.4 ps duration are used to study magnetization reversal in perpendicularly magnetized Co/Pt films. Ring domains, reminiscent of the field contour during exposure, are observed later with Kerr microscopy. Their radii represent switching fields which are in quantitative agreement with the coherent rotation model. The observation of intrinsic transition broadening is attributed to the existence of static and dynamic fluctuations of the magnetic anisotropy.
158 citations
TL;DR: The magnetization and resonance frequencies of submicron Fe magnetic dot arrays were investigated using Brillouin light scattering (BLS) and magneto-optic Kerr Effect (MOKE).
Abstract: The magnetization and resonance frequencies of submicron Fe magnetic dot arrays are investigated using Brillouin light scattering (BLS) and magneto-optic Kerr Effect (MOKE). Large in-plane anisotropies, evident in both the BLS and MOKE results, are traced to shape anisotropies of the individual dots. The measured magnon frequencies are in good agreement with values calculated on the basis of isolated ellipsoids without interdot coupling.
118 citations
TL;DR: In this article, a theoretical study of the nonlinear optical properties of single-shell semiconductor carbon nanotubes (CNs) within a simple model based on the two-band approximation of their electronic structure is presented.
Abstract: We present a theoretical study of the nonlinear-optical properties of single-shell semiconductor carbon nanotubes (CNs) within a simple model based on the two-band approximation of their electronic structure. By use of the Genkin–Mednis approach, we have calculated the nonlinear-optical spectra of the susceptibility χ(3)(ω) for the following third-order polarization effects: the third harmonic generation, the intensity-dependent index of refraction, the two-photon absorption and the DC Kerr effect. It is found that in off-resonant conditions the susceptibility χ(3)(0) shows a four-power dependence on the tubule radius and can reach values typical of bulk III–V semiconductor compounds with the strongest nonlinear optical properties. The optical spectra of χ(3)(ω) under the three-photon resonance regime have revealed considerable enhancement of the radiation power generated at a third-harmonic frequency. Our results show that in CNs the nonlinear index of refraction as large as 2×10−8 cm2 W−1 can be achieved in a region where the two-photon absorption is small. The change of the refractive index of CNs of the order of 10−11E02 (V2 cm−2) was found to be induced by a uniform static electric field E0 applied along the CNs axis. It is concluded that carbon nanotubes present a considerable interest in view of their possible utilization in a variety of nonlinear optical devices.
114 citations
TL;DR: In this paper, self-focusing of ps laser pulses (λ =790 nm) due to the nonlinear Kerr effect is shown to provide an easy and flexible method for producing bulk structures with dimensions on the order of 10 μm without damaging the entrance or exit surfaces of the material.
Abstract: Self-focusing of ps laser pulses (λ=790 nm) due to the nonlinear Kerr effect is shown to provide an easy and flexible method for producing bulk structures with dimensions on the order of 10 μm without damaging the entrance or exit surfaces of the material. The depth at which damage occurs can be controlled by adjusting either the pulse energy or pulse length. A study of the dependence of structure depth on the square root of the laser power for a given pulse length provides a straightforward method for determining the nonlinear index of refraction (Kerr coefficient), n2.
101 citations
TL;DR: In this paper, the whispering gallery modes (WGMs) of fused silica microspheres immersed in a superfluid helium bath have been studied and the authors have observed a dispersive bistable behavior of the WGM resonances with a threshold power of 10 μW.
Abstract: Quality factors up to 109 have been obtained in the whispering gallery modes (WGMs) of fused silica microspheres immersed in a superfluid helium bath. We have observed a dispersive bistable behaviour of the WGM resonances with a threshold power of 10 μW, due to the intrinsic Kerr nonlinearity of silica. These results open the way to the realization of a thresholdless microlaser and other cavity QED projects with microspheres.
92 citations
TL;DR: In this paper, simplified analytic expressions for magneto-optical Kerr effects of both optically thick and ultrathin films in the general case, where a magnetic medium had an arbitrary direction of magnetization and a beam of light was obliquely incident to the medium, were developed.
Abstract: We have developed simplified analytic expressions for magneto-optical Kerr effects of both optically thick and ultrathin films in the general case, where a magnetic medium had an arbitrary direction of magnetization and a beam of light was obliquely incident to the medium It was found that the simplified analytic formulae for the Kerr effects of p and s waves consisted of a product of two factors for both optically thick and ultrathin films: the prefactor dependent only on the optical parameters of the system and the main factor of the polar Kerr effect for a normal incidence case We have also derived some useful relations among the Kerr effects in the polar and longitudinal configurations We have demonstrated that the theoretical calculations using the present analytic formulae could well match the experimental polar and longitudinal Kerr rotation angles of magnetic films measured with varying incident angles
92 citations
TL;DR: The first observation of spatial one-dimensional photorefractive screening solitons in centrosymmetric media is reported and good qualitative agreement with theory is found.
Abstract: We report the first observation of spatial one-dimensional photorefractive screening solitons in centrosymmetric media and compare the experimental results with recent theoretical predictions. We find good qualitative agreement with theory.
86 citations
TL;DR: In this paper, the second-order magneto-optic Kerr effect was investigated in Fe, Co, and NiFe thin films with in-plane anisotropy and compared to theoretical predictions based on an interband transition model.
68 citations
TL;DR: In this paper, the femtosecond optically heterodyned detected optical Kerr effect (OHD-OKE) response of carbon disulfide/pentane binary mixtures is reported for various concentrations.
Abstract: The femtosecond optically heterodyned detected optical Kerr effect (OHD-OKE) response of carbon disulfide/pentane binary mixtures is reported for various concentrations. As pentane is added, three trends are observed: the instantaneous electronic contribution gets more pronounced, the picosecond diffusive reorientation becomes faster, and the subpicosecond inertia-limited response slows down. The corresponding frequency domain representation of the latter component narrows and shifts toward lower frequencies. These spectral changes occur exclusively when the CS2 concentration is lowered from 100 to 20 vol %; at still lower concentrations no further changes are observed. When the nondiffusive part of the optical response is assigned exclusively to coherent intermolecular vibrations, the spectral changes can be attributed to a reduced inhomogeneous broadening, reflecting a narrowing of the distribution of oscillator frequencies. However, we argue here that because of the observed concentration dependence t...
65 citations
TL;DR: In this article, a review paper of basic knowledge and recent advances in the area of spatial solitons in Kerr and Kerr-like media is presented, where the authors consider spatial bright and dark solitions, solITons in waveguide geometries, optical bullets, vortex soliton and, briefly, dissipative cases.
Abstract: This is a review paper of basic knowledge and recent advances in the area of spatial solitons in Kerr and Kerr-like media. We consider spatial bright and dark solitons, solitons in waveguide geometries, optical bullets, vortex solitons and, briefly, dissipative cases. In our treatment, we use a Hamiltonian approach when considering stability issues.
TL;DR: In this paper, the Hartree-Fock-level nuclear relaxation/infinite frequency approximation was evaluated for CF4 and SF6 and it was shown that the nuclear relaxation is of the order of 50% too small.
Abstract: Electrical property derivative expressions are presented for the nuclear relaxation contribution to static and dynamic (infinite frequency approximation) nonlinear optical properties. For CF4 and SF6, as opposed to HF and CH4, a term that is quadratic in the vibrational anharmonicity (and not previously evaluated for any molecule) makes an important contribution to the static second vibrational hyperpolarizability of CF4 and SF6. A comparison between calculated and experimental values for the difference between the (anisotropic) Kerr effect and electric field induced second-harmonic generation shows that, at the Hartree–Fock level, the nuclear relaxation/infinite frequency approximation gives the correct trend (in the series CH4, CF4, SF6) but is of the order of 50% too small.
TL;DR: In this article, the decays of confined methyl iodide are described by the sum of two exponentials, the faster of which has the same decay rate as the bulk liquid, and the slower exponential is interpreted as arising from the hindered reorientational dynamics of liquid molecules on or near the surfaces of the pores.
Abstract: Optical Kerr effect spectroscopy has been used to study the orientational dynamics of liquid methyl iodide in bulk and confined in nanoporous glasses of several different pore sizes. Consistent with the behavior of other nonwetting or weakly wetting liquids, the decays of confined methyl iodide are described well by the sum of two exponentials, the faster of which has the same decay rate as the bulk liquid. The slower exponential is interpreted as arising from the hindered reorientational dynamics of liquid molecules on or near the surfaces of the pores. The rate of surface reorientation depends significantly on the pore diameter, which along with other evidence suggests that the retardation of surface dynamics arises through geometric effects.
TL;DR: In this paper, an optical Kerr effect experiment was performed on liquid and supercooled liquid salol, in order to test some predictions of the mode-coupling theory of the liquid-glass transition.
Abstract: We report an optical Kerr effect experiment, performed on liquid and supercooled liquid salol, in order to test some predictions of the mode-coupling theory of the liquid-glass transition. We show that this experiment is sensitive mostly to the reorientational motion of the molecules and the corresponding correlation function exhibits, above the critical temperature ${T}_{C},$ a von Schweidler relaxation followed by an \ensuremath{\alpha} relaxation regime. The critical temperature and the critical exponent derived from the analysis of the experiment are in good agreement with the same quantities previously determined, in the frequency domain, through a depolarized light-scattering experiment, by Li et al. [Phys. Rev. B 46, 3343 (1992)].
TL;DR: In this paper, a femtosecond optical Kerr effect experiment has been used to study the dynamic process of third-order optical nonlinearity for organic solvents at femto-conditional time scales.
Abstract: A femtosecond optical Kerr effect experiment has been used to study the dynamic process of third-order optical nonlinearity for organic solvents acetone, acetonitrile, alcohol, benzene, chloroform, dichlomathane, dimenthylsulfoxande, dioxane, ethanol, and methanol, etc. The nonlinear refractive index for the solvents at femtosecond time scale was measured.
TL;DR: In this paper, a spatiotemporal model for the evolution process of the pulse and beam shapes in femtosecond Kerr-lens mode-locked solid-state lasers is presented.
Abstract: A spatiotemporal model for the evolution process of the pulse and beam shapes in femtosecond Kerr-lens mode-locked solid-state lasers is presented. For different cavity configurations we comprehensively studied the dependence of the pulse and beam parameters on laser-control parameters such as pump rate, linear phase dispersion up to fourth order, self-phase modulation, and self-amplitude modulation owing to nonlinear resonator transmission. We determine the conditions for the ultimate shortest pulse duration. The influence of third- and fourth-order dispersion results in spectral sidebands, which are phase matched with the peak of the principal spectrum. Excessive fourth-order dispersion yields a steady-state multipulse operating regime with constant peak separation.
TL;DR: In this paper, the authors apply the characteristic directions theory of photoelasticity to understand the fringes of point/plane electrodes in transformer oil and show that simplifications in the characteristic parameter theory are possible, resulting in simple integral relationships between the characteristic parameters and the applied electric field.
Abstract: Differential equations that govern light propagation in Kerr media are derived when the applied electric field direction and magnitude vary along the light path. Case studies predict Kerr electro-optic fringe patterns for the specific case of point/plane electrodes. We apply the characteristic directions theory of photoelasticity to understand these fringes. We also study birefringent media with small Kerr constant, in particular transformer oil. For this case we show that simplifications in the characteristic parameter theory is possible, resulting in simple integral relationships between the characteristic parameters and the applied electric field. We use these simple relationships to extend the ac modulation method to measure the characteristic parameters for small Kerr constant media. Measurements of the characteristic parameters using the ac modulation method are presented for point/plane electrodes in transformer oil. The measurements agree reasonably well with space charge free theory for infinite extent electrodes for which analytical expressions are available. We finally employ the 'onion peeling' method to reconstruct the axisymmetric electric field magnitude and direction from the measured characteristic parameters and compare the results to the analytically obtained electric field.
TL;DR: In this article, the magnetic properties of large scale periodic magnetic nanostructures designed as dot-arrays with periodicity ranging between 300 nm and 1100 nm, consisting of Co/Pt multilayer dots with respective diameters ranging between 230 nm and 740 nm.
Abstract: We report on the magnetic properties of large scale periodic magnetic nanostructures designed as dot-arrays with periodicity ranging between 300 nm and 1100 nm, consisting of Co/Pt multilayer dots with respective diameters ranging between 230 nm and 740 nm. The nanostructures are fabricated by using optical interference lithography allowing for large area (cm/sup 2/) fabrication. The Co/Pt multilayer dots show a pronounced out-of-plane magnetic anisotropy. The magnetic properties are determined from magneto-optical Kerr effect measurements in polar geometry and results are compared to respective continuous Co/Pt multilayer thin films. The micromagnetic properties of both, films and nanostructures are investigated with magnetic force microscopy allowing for the application of an external perpendicular magnetic field of up to B=0.15 T.
TL;DR: A numerical analysis reveals that the spectral chirp generated by the plasma nonlinearity is to a good approximation linear over the whole pulse spectrum and can be compensated in a dispersive delay line.
Abstract: We investigate the evolution of optical pulses in a hollow waveguide filled with noble gas at pulse intensities for which tunnel ionization dominates the nonlinear response of the gas. A numerical analysis reveals that the spectral chirp generated by the plasma nonlinearity is to a good approximation linear over the whole pulse spectrum and can be compensated in a dispersive delay line. Our calculations predict the generation of 3–4-fs optical pulses with energies of a few milijoules. To our knowledge, these energies are an order of magnitude greater than the pulse energies that have been realized to date in hollow-fiber compressors based exclusively on the nonlinear Kerr effect.
Abstract: We present the formalism within which all second and third order nonlinear susceptibility coefficients can be calculated from the Landau expansion for an isotropic paraelectric phase by means of the Landau-Khalatnikov dynamical equations. Both first-order and second-order phase transitions are considered. Detailed results are given for all the second-order coefficients in the ferroelectric phase and for third harmonic generation, intensity-dependent refractive index and d.c. Kerr effect in both paraelectric and ferroelectric phases.
TL;DR: This work analytically studies the influence of this induced cubic nonlinearity on the amplitude and phase modulation of the fundamental wave and predicts efficient all-optical switching.
Abstract: Recently it was shown that in quasi-phase-matched quadratic media the average intensities are subject to an induced Kerr effect. We analytically study the influence of this induced cubic nonlinearity on the amplitude and phase modulation of the fundamental wave and predict efficient all-optical switching.
TL;DR: In this paper, a scanning near-field optical microscope is combined with a modified Sagnac interferometer to generate high-resolution magnetic contrast images of a magneto-optical disk (MOD) in reflection.
Abstract: A scanning near-field optical microscope is combined with a modified Sagnac interferometer to generate high-resolution magnetic contrast images of a magneto-optical disk (MOD) in reflection. The interferometer acts as a magnetic sensor to determine the Kerr rotation of reflected circularly polarized light. A separate shear-force sample topography is obtained simultaneously with the optical. This technique allows successful magnetic imaging of samples with complicated surface topographies, as demonstrated with the MOD. For these initial measurements, the resolution with nonmetal-coated fiber tips is 300 nm, and the magnetic phase sensitivity is 1 mrad.
TL;DR: In this paper, phase properties of the field interacting with a two-level atom in a lossless cavity Jaynes-Cummings model, taking into account the level shifts produced by Stark effect with an additional Kerr medium for one-mode are studied using the phase formalism of Pegg and Barnett.
Abstract: Phase properties of the field interacting with a two-level atom in a lossless cavity Jaynes-Cummings model, taking into account the level shifts produced by Stark effect with an additional Kerr medium for one-mode are studied using the phase formalism of Pegg and Barnett. It is shown in particular that phase properties of the field reflect the collapse and revival phenomena. The results for the time evolution of the phase probability distribution and the phase fluctuations are obtained. The effect of Stark shift on the phase properties in both the absence and presence of a Kerr medium is analyzed. Phase localization is found for certain choice of the parameters.
TL;DR: In this paper, the second-order hyperpolarizability of C 60 and its derivative C 60 -poly-aminonitrile was measured using a femtosecond time-resolved optical Kerr effect.
TL;DR: In this paper, a quasistatic approximation is used to calculate local-enhancement factors for the second and third harmonic generation, degenerate four-wave mixing, and nonlinear Kerr effect.
Abstract: Nonlinear optical phenomena on rough self-affine metal surfaces are theoretically studied. Placing nonlinearly polarizable molecules on such surfaces results in strong enhancement of optical nonlinearities. A quasistatic approximation is used to calculate local-enhancement factors for the second and third harmonic generation, degenerate four-wave mixing, and nonlinear Kerr effect. The calculations show that the average enhancement factors on a self-affine surface can be as large as ${10}^{7}$ and ${10}^{15}$ for optical nonlinearities of the second and third order, respectively, with the maximum average enhancement in the infrared spectral range. Strong spatial inhomogeneity of local-enhancement distribution is demonstrated for the second and third harmonic generation. The local enhancement can exceed the average by several orders of magnitude, reaching extremely high values. Sharp peaks in local-field intensities at fundamental and generated frequencies are localized in spatially separated nanometer-sized areas of the film.
TL;DR: On the basis of simple physical arguments involving energy flows and power invariants, the authors showed that non-paraxiality stabilizes 1+2D soliton beams in Kerr media.
Abstract: On the basis of simple physical arguments involving energy flows and power invariants, we show that nonparaxiality stabilizes 1+2D soliton beams in Kerr media.
TL;DR: In this article, a theoretical model of ultrafast dynamics in the optical Kerr effect in molecular liquids is developed, which assumes that for short times there exist dynamic quasicrystalline structures including a central molecule and its nearest neighbors.
Abstract: A theoretical model of ultrafast dynamics in the optical Kerr effect in molecular liquids is developed. It assumes that for short times there exist dynamic quasicrystalline structures including a central molecule and its nearest neighbors. The interaction of such structures with a femtosecond laser pulse leads to excitation of vibrational modes (local phonons) which are responsible for subpicosecond nonlinear polarizability of the liquid. The results of numerical calculations performed for benzene show a very good agreement with the experimental data. The lifetime of the dynamic quasicrystalline structures in benzene, at room temperature, is estimated to be about 200 fs.
TL;DR: In this article, a combination of in-situ stress measurements with low-energy electron diffraction and scanning tunneling microscopy is used to investigate structural transitions during film growth and the influence of structural changes on the magnetic properties of Fe films is examined with magneto-optical Kerr effect measurements.
TL;DR: In this article, the conductivity tensor of polycrystalline Pt{sub 3}X (X=Mn,thinspCo) was determined between 1.6 and 5.2thinspeV.
Abstract: The conductivity tensor of polycrystalline Pt{sub 3}X (X=Mn,thinspCo) was determined between 1.6 and 5.2thinspeV.. Samples were arc melted, mechanically polished, and annealed at 500thinsp{degree}C for 1thinsph in Ar. The complex dielectric function was measured from 1.3 to 5.2thinspeV at room temperature with a rotating analyzer ellipsometer. The magneto-optic Kerr effect was studied between 10 and 293thinspK in magnetic fields up to 3thinspT. We used the tight-binding linear-muffin-tin-orbital method in the local spin-density approximation to determine the band structure, density of states, and optical conductivity. Including an empirical quasiparticle self-energy and a lifetime broadening yields good agreement of experimental and calculated spectra. {copyright} {ital 1998} {ital The American Physical Society}
01 Apr 1998-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this article, the magnetization in the films were measured by means of Perturbed Angular Correlation (PAC) spectroscopy with implanted 111In tracer ions, or the Magneto-Optic Kerr Effect (MOKE).
Abstract: 100–300 nm thin Fe layers evaporated onto crystalline and amorphous Si or SiO2 substrates were irradiated, at 77 K, with 1014–1016 Xe+-ions/cm2 at 450 keV beam energy. The magnetizations in the films were measured by means of Perturbed Angular Correlation (PAC) spectroscopy with implanted 111In tracer ions, or the Magneto-Optic Kerr Effect (MOKE). Upon ion implantation, dramatic changes of the magnetic anisotropy were observed which are attributed to ion-beam enhanced lateral grain growth. Very little influence of the deposition parameters (type and cristallinity of substrate, evaporation rate) on the anisotropic magnetization was found.