Interaction of Cotton-Mouton and Faraday effect under different initial polarization state of incident beam

2010 ◽  
Author(s):  
J. Chrzanowski ◽  
Yu. A. Kravtsov
Keyword(s):  
Faraday Effect ◽  
Polarization State ◽  
Incident Beam ◽  
Initial Polarization

“Acceptor impurity” mode in 1-D holographic photonic crystals achieved by controlling polarization state of the incident beam

2004 ◽  
Vol 241 (4-6) ◽  
pp. 357-364 ◽  
Author(s):  
Kun Ren ◽  
Xiaobin Ren ◽  
Rong Li ◽  
Jing Zhou ◽  
Dahe Liu ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Polarization State ◽  
Incident Beam ◽  
Acceptor Impurity

scholarly journals A simple analytical model of the angular momentum transformation in strongly focused light beams

Open Physics ◽  
2010 ◽  
Vol 8 (6) ◽  
Author(s):  
Aleksandr Bekshaev
Keyword(s):  
Angular Momentum ◽  
Cross Section ◽  
Field Distribution ◽  
Orbital Angular Momentum ◽  
Polarization State ◽  
Incident Beam ◽  
Quantitative Agreement ◽  
Beam Polarization ◽  
Circular Aperture ◽  
Analytical Results

AbstractA ray-optics model is proposed to describe the vector beam transformation in a strongly focusing optical system. In contrast to usual approaches based on the focused field distribution near the focal plane, we use the beam pattern formed immediately after the exit aperture. In this cross section, details of the output field distribution are of minor physical interest but proper allowance is made for transformation of the beam polarization state. This enables the spin and orbital angular momentum representations to be obtained, which are valid for any cross section of the transformed beam. Simple analytical results are available for a transversely homogeneous, circularly polarized incident beam confined by a circular aperture. Variations of the spin and orbital angular momenta of the output beam with change of the focusing strength are analyzed. The analytical results are in good qualitative and reasonable quantitative agreement with the results of numerical calculations performed for the Gaussian and Laguerre-Gaussian beams. The model supplies an efficient and physically transparent means for qualitative analysis of the spin-to-orbital angular momentum conversion. It can be generalized to incident beams with complex spatial and polarization structure.

scholarly journals Instrument-independent specification of the diffraction geometry and polarization state of the incident X-ray beam

2008 ◽  
Vol 42 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Marc Schiltz ◽  
Gérard Bricogne
Keyword(s):  
Bragg Reflection ◽  
Polarization State ◽  
Azimuthal Angle ◽  
Incident Beam ◽  
Stokes Parameters ◽  
Anomalous Scattering ◽  
X Ray ◽  
Data Processing Software ◽  
Diffraction Geometry ◽  
Definition Of

This work augments the proposal of Schwarzenbach & Flack [J. Appl. Cryst.(1989),22, 601–605], who have advocated the use of a diffractometer-independent definition of the azimuthal angle ψ to specify the diffraction geometry of a Bragg reflection. It is here proposed that one additional angle ξ, which is also based on a diffractometer-independent definition, is needed to encode the direction of linear polarization for those experiments where this quantity is of importance. This definition is then extended to the cases of partially and/or elliptically polarized X-ray beams, and the use of three normalized Stokes parameters,P1,P2andP3, together with ξ, is advocated in order to characterize exhaustively the polarization state of the incident beam. The conventions proposed here present a general, unambiguous and economical means of encoding the information about the diffraction geometry, without the need to record any further information about the instrument, crystal orientation matrix and goniometer angles. Data-processing software using these definitions to analyse polarization-dependent phenomena becomes instrument-independent and completely general. These methods have been implemented in the macromolecular phasing programSHARPfor exploiting the polarization anisotropy of anomalous scattering in protein crystals.

scholarly journals Shifts of Coherent Light Beams on Reflection at Plane Interfaces between Isotropic Media

1980 ◽  
Vol 33 (2) ◽  
pp. 319 ◽  
Author(s):  
RG Turner
Keyword(s):  
Large Range ◽  
Polarization State ◽  
Incident Beam ◽  
Theoretical Work ◽  
Beam Profile ◽  
Theoretical Treatment ◽  
Coherent Light ◽  
Theoretical Approaches ◽  
Isotropic Media ◽  
Light Beams

Previous experimental and theoretical work on both longitudinal and transverse shifts of light beams at totally reflecting interfaces is briefly reviewed and the discrepancy between the predictions of the two principal theoretical approaches is discussed. A theoretical treatment, valid for an interface between any two media, is presented. The intensity profile of the reflected beam is the same as that of the incident beam (albeit shifted in the reflecting interface) only for certain polarization states of the incident beam and provided that the reflection parameters of the interface meet certain conditions. If these conditions are not met the reflected beam profile suffers distortion and, possibly, deviation from its expected direction. Because the polarization state of a beam is, in general, altered by reflection, measurements of the shifts over a large range of angles of incidence at a single reflection are needed in order to verify the predictions.

Atomic spins as a storage medium for quantum fluctuations of light

2003 ◽  
Vol 3 (special) ◽  
pp. 518-534
Author(s):  
B. Julsgaard ◽  
C. Schori ◽  
J. L. Sorensen ◽  
E.S. Polzik
Keyword(s):  
Faraday Effect ◽  
Stark Effect ◽  
Polarization State ◽  
Quantum Memory ◽  
Storage Medium ◽  
Atomic Spin ◽  
Matter Interaction ◽  
Dynamic Stark Effect ◽  
Atomic Spins ◽  
Light Matter Interaction

We review recent results showing the possibility to use off-resonant light/matter interaction for the purpose of quantum memory. A quantum state of atomic spins can be read out by light in a process which is a quantum analogue of the classical Faraday effect. Conversely, the dynamic Stark effect opens up the opportunity for recording the polarization state of light onto the atomic spin memory. We demonstrate that a sample of cesium atoms under appropriate conditions has the sensitivity to record properties of just a few photons, thus being a feasible candidate for quantum memory for light.

Instrumentation for detecting channelling radiation in the high-voltage electron microscope

1983 ◽  
Vol 41 ◽  
pp. 318-319
Author(s):  
J. H. Butler ◽  
C. J. Humphreys
Keyword(s):  
Monochromatic Light ◽  
Incident Beam ◽  
Laboratory Frame ◽  
Relativistic Electrons ◽  
Voltage Electron ◽  
Dipole Emission ◽  
Sinusoidal Oscillations ◽  
Pass Through ◽  
Incident Beam Energy ◽  
Increasing Function

Electromagnetic radiation is emitted when fast (relativistic) electrons pass through crystal targets which are oriented in a preferential (channelling) direction with respect to the incident beam. In the classical sense, the electrons perform sinusoidal oscillations as they propagate through the crystal (as illustrated in Fig. 1 for the case of planar channelling). When viewed in the electron rest frame, this motion, a result of successive Bragg reflections, gives rise to familiar dipole emission. In the laboratory frame, the radiation is seen to be of a higher energy (because of the Doppler shift) and is also compressed into a narrower cone of emission (due to the relativistic “searchlight” effect). The energy and yield of this monochromatic light is a continuously increasing function of the incident beam energy and, for beam energies of 1 MeV and higher, it occurs in the x-ray and γ-ray regions of the spectrum. Consequently, much interest has been expressed in regard to the use of this phenomenon as the basis for fabricating a coherent, tunable radiation source.

Arsenic segregation in polysilicon

1983 ◽  
Vol 41 ◽  
pp. 154-155 ◽  
Author(s):  
P.E. Batson ◽  
C.R.M. Grovenor ◽  
D.A. Smith ◽  
C. Wong
Keyword(s):  
Incident Beam ◽  
Silicon Wafers ◽  
Chemical Polishing ◽  
Bright Field Image ◽  
Beam Size ◽  
Stem Analysis ◽  
Bright Field ◽  
Twin Boundaries ◽  
X Ray ◽  
Line Scan

In this work As doped polysilicon was deposited onto (100) silicon wafers by APCVD at 660°C from a silane-arsine mixture, followed by a ten minute anneal at 1000°C, and in one case a further ten minute anneal at 700°C. Specimens for TEM and STEM analysis were prepared by chemical polishing. The microstructure, which is unchanged by the final 700°C anneal,is shown in Figure 1. It consists of numerous randomly oriented grains many of which contain twins.X-ray analysis was carried out in a VG HB5 STEM. As K α x-ray counts were collected from STEM scans across grain and twin boundaries, Figures 2-4. The incident beam size was about 1.5nm in diameter, and each of the 20 channels in the plots was sampled from a 1.6nm length of the approximately 30nm line scan across the boundary. The bright field image profile along the scanned line was monitored during the analysis to allow correlation between the image and the x-ray signal.

Resolution Attainable With the Present Day STEM

1973 ◽  
Vol 31 ◽  
pp. 230-231 ◽  
Author(s):  
J. S. Wall ◽  
J. P. Langmore ◽  
H. Isaacson ◽  
A. V. Crewe
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Incident Beam ◽  
Scanning Transmission Electron Microscope ◽  
Aperture Size ◽  
Magnetic Lens ◽  
Peak Intensity ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Half Angle

The scanning transmission electron microscope (STEM) constructed by the authors employs a field emission gun and a 1.15 mm focal length magnetic lens to produce a probe on the specimen. The aperture size is chosen to allow one wavelength of spherical aberration at the edge of the objective aperture. Under these conditions the profile of the focused spot is expected to be similar to an Airy intensity distribution with the first zero at the same point but with a peak intensity 80 per cent of that which would be obtained If the lens had no aberration. This condition is attained when the half angle that the incident beam subtends at the specimen, 𝛂 = (4𝛌/Cs)¼

Symmetries and Extinction Rules in CBED

1982 ◽  
Vol 40 ◽  
pp. 684-685
Author(s):  
K. Ishizuka
Keyword(s):  
Electron Diffraction ◽  
Incident Beam ◽  
Convergent Beam Electron Diffraction ◽  
Beam Direction ◽  
Beam Electron ◽  
Convergent Beam

The technique of convergent-beam electron diffraction (CBED) has been established. However there is a distinct discrepancy concerning the CBED pattern symmetries associated with translation symmetries parallel to the incident beam direction: Buxton et al. assumed no detectable effects of translation components, while Goodman predicted no associated symmetries. In this report a procedure used by Gjønnes & Moodie1 to obtain dynamical extinction rules will be extended in order to derive the CBED pattern symmetries as well as the dynamical extinction rules.

Remarks on the application of backscattered electron imaging (BEI) to the scanning electron microscopy (SEM) of biological structures

1983 ◽  
Vol 41 ◽  
pp. 484-487
Author(s):  
Etienne de Harven
Keyword(s):  
High Resolution ◽  
Incident Beam ◽  
Spot Size ◽  
Primary Electron ◽  
Critical Point Drying ◽  
Cell Shapes ◽  
High Resolution Images ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
Scanning Electron

Biological ultrastructures have been extensively studied with the scanning electron microscope (SEM) for the past 12 years mainly because this instrument offers accurate and reproducible high resolution images of cell shapes, provided the cells are dried in ways which will spare them the damage which would be caused by air drying. This can be achieved by several techniques among which the critical point drying technique of T. Anderson has been, by far, the most reproducibly successful. Many biologists, however, have been interpreting SEM micrographs in terms of an exclusive secondary electron imaging (SEI) process in which the resolution is primarily limited by the spot size of the primary incident beam. in fact, this is not the case since it appears that high resolution, even on uncoated samples, is probably compromised by the emission of secondary electrons of much more complex origin.When an incident primary electron beam interacts with the surface of most biological samples, a large percentage of the electrons penetrate below the surface of the exposed cells.

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