Search results for "Dispersion."
showing 10 items of 1094 documents
Singlet ground state magnetism: III. magnetic excitons in antiferromagnetic TbP
1981
The dispersion of the lowest magnetic excitations of the singlet ground state system TbP has been studied in the antiferromagnetic phase by inelastic neutron scattering. The magnetic exchange interaction and the magnetic and the rhombohedral molecular fields have been determined.
Magnetic excitations of the singlet ground state antiferromagnet CsFeBr3 in a magnetic field
1991
Abstract The magnetic excitations in the quasi-one-dimensional singlet ground state antiferromagnet CsFeBr3 have been studied by inelastic neutron scattering in the presence of an applied magnetic field, H‖c and H⊥c. With H‖c, the dispersion curves renormalise so that the exchange interaction has a decreasing influence with increasing field. H⊥c has little or no effect on the dispersion of the magnetic excitations.
NGC1600 - Cluster or Field Elliptical?
2008
A study of the galaxy distribution in the field of the elliptical galaxy NGC1600 has been undertaken. Although this galaxy is often classified as a member of a loose group, all the neighbouring galaxies are much fainter and could be taken as satellites of NGC1600. The number density profile of galaxies in the field of this galaxy shows a decline with radius, with evidence of a background at approximately 1.3 Mpc. The density and number density profile are consistent with that found for other isolated early-type galaxies. NGC1600 appears as an extended source in X-rays, and the center of the X-ray emission seems not to coincide with the center of the galaxy. The velocity distribution of neig…
Generating ultra-short high-energy pulses using dissipative soliton resonance: Pulse compression schemes
2011
Dissipative soliton resonance (DSR) refers to a phenomenon where the energy of the stable soliton solution increases to extremely large values in a nonlinear dissipative system modeled by the complex cubic-quintic Ginzburg-Landau equation (CGLE) [1]. It occurs in the vicinity of a specific hyper-surface in the multi-dimensional space of the CGLE parameters. The phenomenon has applications in designing laser oscillators generating ultra-high energy pulses, since the dynamics of such lasers can be well-modeled by the CGLE. The DSR was first found in normally-dispersive media, in concordance with the current design trend for high-energy mode-locked laser oscillators [2–4]. However, we have sho…
Optimization of soliton transmissions in dispersion-managed fiber links
1998
We propose a simple optimization criterion (including the best launch point position in-between amplifiers) for the design of soliton transmission lines. The present approach is shown to minimize energy scattering from the solitons into the continuum.
Perturbations, internal modes and noise in dispersion-managed soliton transmission
2005
We apply the theory of soliton internal modes to characterize the dynamics of small perturbations in the dispersion-managed soliton transmission regime. We extend our study to the case of random initial perturbations calculating several realizations and obtaining accurate descriptions of their statistics.
Time-multiplexed chromatic-controlled axial diffractive optical elements
2010
Programmable diffractive optical elements DOEs with axial response have many interesting applications, including diffractive lenses, axicons, and optical tweezers. In all these cases, it is essential to properly select the modulation configuration of the spatial light modulator SLM where the DOE is displayed, in order to avoid the undiffracted zero order component that appears on axis and overlaps the desired axial response. However, in general, the chromatic dispersion in liquid crystal SLMs prevents the cancellation of the zero order for a broadband light source, thus limiting the possibilities for polychromatic program- mable axial DOEs. We operate a ferroelectric liquid crystal on silic…
Nonlocal field correlations and dynamical Casimir-Polder forces between one excited- and two ground-state atoms
2006
The problem of nonlocality in the dynamical three-body Casimir-Polder interaction between an initially excited and two ground-state atoms is considered. It is shown that the nonlocal spatial correlations of the field emitted by the excited atom during the initial part of its spontaneous decay may become manifest in the three-body interaction. The observability of this new phenomenon is discussed.
160-GHz picosecond pulse train generation through multiwave mixing compression of a dual frequency beat signal
2002
We report the experimental generation and characterization of a 160-GHz picosecond puise train using multiple four-wave mixing temporal compression of an initial dual frequency beat signal in the anomalous-dispersion regime of a non-zero dispersion shifted fiber.
Elementary excitations in superfluidH3e-H4emixtures
2010
We have studied the dynamic structure function of superfluid $^{3}\text{H}\text{e-}^{4}\text{H}\text{e}$ mixtures at zero temperature as a function of pressure and $^{3}\text{H}\text{e}$ concentration. Results obtained in the full random-phase approximation (RPA) plus density-functional theory and in a generalized Landau-Pomeranchuk approach are presented and compared with experiment. Analytic expressions for several sum rules of the dynamic structure functions have been determined, and have been used to obtain average energies of the collective excitations. In the RPA approach, the dispersion relation of the collective modes shows typical features of level repulsion between zero-soundlike …