Search results for "polarization."

Origin of Kerr effect: investigation of solutions by polarization dependent Z-scan

2020

This material is based upon work supported by the ERDF 1.1.1.1 activity project No. 1.1.1.1/16/A/046 “Application assessment of novel organic materials by prototyping of photonic devices”.

Transition from polarization disorder to antiphase polarization domains in a fiber laser

2014

Adjusting polarization coupling in a fiber ring laser may lead to anti-synchronization of spatio-temporal disorder into ordered laminar states of orthogonal polarization temporal domains, as well as stable lattices of soliton trains.

Numerical modelling of the galvanic coupling in aluminium alloys: A discussion on the application of local probe techniques

2010

Abstract A discussion is proposed on the determination of the input values and the experimental validation of finite element modelling of the galvanic coupling in aluminium alloys by local probe techniques such as the Scanning Vibrating Electrode Technique (SVET) and the microcapillary electrochemical cell (microcell). Polarization curves obtained by the microcell were introduced as input conditions in the model based on Laplace or Nernst–Planck equation. SVET measurements were performed to determine the coupling current distribution on an Al/Al4%Cu bimetallic system. Agreement was found between simulated and experimental current distributions depending on the input conditions and the solve…

Assessment of age-related skin changes using hyperspectral polarization imaging

2019

Abstract We report a development of hyperspectral polarization imaging approach for assessment of age-related skin changes. The degree of residual polarization is used as a quantitative marker of the age-related pathological malformations. The developed approach in frame of express analysis of the degree of residual polarization in each pixel of the image are shown.

Germanium microparticles as optically induced oscillators in optical tweezers

2019

Oscillatory dynamics is a key tool in optical tweezers applications. It is usually implemented by mechanical interventions that cannot be optically controlled. In this work we show that Germanium semiconductor beads behave as optically induced oscillators when subjected to a highly focused laser beam. Such unusual motion is due to the competition between the usual optical forces [1-3] and the radiometric force related to thermal effects, which pushes the beads from the focal region [4]. We characterize the behavior of the Germanium beads in detail and propose a model accounting for the related forces, in good agreement with the experimental data. The well defined direction of oscillations c…

2018

Abstract When electrochemical techniques are used to probe the surface of corroding magnesium with the aim of obtaining quantitative information on the corrosion process, two peculiarities are generally observed: i) with anodic polarization, the rate of hydrogen evolution increases instead of decreasing and ii) during electrochemical impedance spectroscopy measurements, an inductive contribution is often observed at the low-frequency end of the spectra. The presence of these two phenomena clearly has an impact on the methodology that should be applied to correctly estimate corrosion rates from electrochemical data. The aim of this work is to provide a general mathematical description of the…

Spin Hall magnetoresistance in the non-collinear ferrimagnet GdIG close to the compensation temperature

2017

We investigate the spin Hall magnetoresistance (SMR) in a gadolinium iron garnet (GdIG)/platinum (Pt) heterostructure by angular dependent magnetoresistance measurements. The magnetic structure of the ferromagnetic insulator GdIG is non-collinear near the compensation temperature, while it is collinear far from the compensation temperature. In the collinear regime, the SMR signal in GdIG is consistent with the usual [Formula: see text] relation well established in the collinear magnet yttrium iron garnet, with [Formula: see text] the angle between magnetization and spin Hall spin polarization direction. In the non-collinear regime, both an SMR signal with inverted sign and a more complex an…

Development of a scanning electron microscopy with polarization analysis system for magnetic imaging with ns time resolution and phase-sensitive dete…

2018

Scanning electron microscopy with polarization analysis is a powerful lab-based magnetic imaging technique offering simultaneous imaging of multiple magnetization components and a very high spatial resolution. However, one drawback of the technique is the long required acquisition time resulting from the low inherent efficiency of spin detection, which has limited the applicability of the technique to certain quasi-static measurement schemes and materials with high magnetic contrast. Here we demonstrate the ability to improve the signal-to-noise ratio for particular classes of measurements involving periodic excitation of the magnetic structure via the implementation of a digital phase-sens…

Is light narrowing possible with dense-vapor paraffin coated cells for atomic magnetometers?

2017

We investigated the operation of an all-optical rubidium-87 atomic magnetometer with amplitude-modulated light. To study the suppression of spin-exchange relaxation, three schemes of pumping were implemented with room-temperature and heated paraffin coated vacuum cells. Efficient pumping and accumulation of atoms in the F=2 ground state were obtained. However, the sought-for narrowing of the resonance lines has not been achieved. A theoretical analysis of the polarization degree is presented to illustrate the absence of light narrowing due to radiation trapping at high temperature.

Spin polarization of magnetoresistive materials by point contact spectroscopy

2003

In the strive to find a straightforward method for determining the spin polarization, the analysis of the Andreev reflection process in point contact junctions has attracted much interest. However, the prerequisite for anevaluation of the transport spin polarization in this scheme is the existence of elastic (ballistic or diffusive) transport, which cannot be assumed a priori. We therefore also include inelastic processes in our analysis and exemplify that thermal effects can have a significant effect on data evaluation. As ferromagnetic samples with a predicted half metallic behavior and comparably low conductivity we used thin films of the double perovskite Sr 2 FeMoO 6 and bulk material …