Search results for "Oscillator"

A fully manipulable damped driven harmonic oscillator using optical levitation

2020

We implement an experimental system based on optical levitation of a silicone oil droplet to demonstrate a damped driven harmonic oscillator. The apparatus allows us to control all the parameters present in the differential equation that theoretically describes such motion. The damping coefficient and driving force can be manipulated in situ by changing the pressure in the apparatus and by applying a variable electric field. We present two different experimental procedures. First, a transition from the overdamped to underdamped regimes is demonstrated by gradually lowering the air pressure. The characteristic resonance associated with an underdamped driven harmonic oscillator is observed by…

Demonstration of polarization pulling in a fiber-optical parametric amplifier

2012

International audience; We report the experimental demonstration of all-optical polarization pulling of an initially polarization-scrambled signal using a fiber-optical parametric amplifier. Nonlinear polarization pulling has been achieved for both the signal and idler with 25 dB gain.

A class of nilpotent Lie algebras admitting a compact subgroup of automorphisms

2017

Abstract The realification of the ( 2 n + 1 ) -dimensional complex Heisenberg Lie algebra is a ( 4 n + 2 ) -dimensional real nilpotent Lie algebra with a 2-dimensional commutator ideal coinciding with the centre, and admitting the compact algebra sp ( n ) of derivations. We investigate, in general, whether a real nilpotent Lie algebra with 2-dimensional commutator ideal coinciding with the centre admits a compact Lie algebra of derivations. This also gives us the occasion to revisit a series of classic results, with the expressed aim of attracting the interest of a broader audience.

Emergence of extreme events in fiber-based parametric processes driven by a partially incoherent pump wave

2009

Modulation instability (MI) generated by a picosecond coherent pulse has been recently identified as the key element of the generation of optical rogue-waves in supercontinuum-based systems [1]. Similar rare but highly energetic pulse structures can also appear in non-solitonic configurations such as Raman amplifiers driven by a partially incoherent pump wave propagating in fibres with low group velocity dispersion [2]. Therefore, one may wonder whether optical rogue-like event can also occur in MI-based amplifier because both Raman and parametric amplifiers benefit from a quasi-instantaneous gain. We provide here experimental evidence of rare optical events in a parametric amplifier in pre…

On Functions of Integrable Mean Oscillation

2005

Given we denote by the modulus of mean oscillation given by where is an arc of , stands for the normalized length of , and . Similarly we denote by the modulus of harmonic oscillation given by where and stand for the Poisson kernel and the Poisson integral of respectively. It is shown that, for each , there exists such that

Deformed Canonical (anti-)commutation relations and non-self-adjoint hamiltonians

2015

Solution of the Skyrme–Hartree–Fock–Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis.

2012

We describe the new version (v2.38j) of the code hfodd which solves the nuclear SkyrmeHartree-Fock or Skyrme-Hartree-Fock-Bogolyubov problem by using the Cartesian deformed harmonic-oscillator basis. In the new version, we have implemented: (i) projection on good angular momentum (for the Hartree-Fock states), (ii) calculation of the GCM kernels, (iii) calculation of matrix elements of the Yukawa interaction, (iv) the BCS solutions for statedependent pairing gaps, (v) the HFB solutions for broken simplex symmetry, (vi) calculation of Bohr deformation parameters, (vii) constraints on the Schiff moments and scalar multipole moments, (viii) the D T transformations and rotations of wave functio…

The algebra eigenstates method for some systems with spin-like interactions

2006

International audience; An extension of the algebra eigenstates formalism is proposed to solve the eigenvalue equation for a class of problems involving "spin interactions". The method is detailed for the harmonic oscillator, su(2) and su(1, 1) algebras. Special emphasis is given to the resolution of problems in vibronic spectroscopy involving doubly degenerate electronic states.

Isoelectronic series of oxygen deficient centers in silica: experimental estimation of homogeneous and inhomogeneous spectral widths

2008

We report nanosecond time-resolved photoluminescence measurements on the isoelectronic series of oxygen deficient centers in amorphous silica related to silicon, germanium and tin atoms, which are responsible of fluorescence activities at approximately 4 eV under excitation at approximately 5 eV. The dependence of the first moment of their emission band on time and that of the radiative decay lifetime on emission energy are analyzed within a theoretical model able to describe the effects introduced by disorder on the optical properties of the defects. We obtain separate estimates of the homogeneous and inhomogeneous contributions to the measured emission line width, and we derive homogeneou…

Deriving electrophysiological brain network connectivity via tensor component analysis during freely listening to music

2020

Recent studies show that the dynamics of electrophysiological functional connectivity is attracting more and more interest since it is considered as a better representation of functional brain networks than static network analysis. It is believed that the dynamic electrophysiological brain networks with specific frequency modes, transiently form and dissolve to support ongoing cognitive function during continuous task performance. Here, we propose a novel method based on tensor component analysis (TCA), to characterize the spatial, temporal, and spectral signatures of dynamic electrophysiological brain networks in electroencephalography (EEG) data recorded during free music-listening. A thr…