Polarization Plane Research Articles

Angle-differential cross sections for Rayleigh scattering of highly linearly polarized hard x rays on Au atoms

We perform a study on Rayleigh scattering of highly linearly polarized hard x rays on a thin Au foil target. In the study the angular distribution of the scattered radiation is analyzed in a relativistic regime both within and out of the plane of polarization of the incident beam. Within this experiment we scatter a synchrotron beam with a photon energy of 175 keV on a high-$Z$ target foil, namely, gold. Our findings correlate well with state-of-the-art calculations of the scattering process performed in the framework of quantum electrodynamics and may have considerable impact on future experiments regarding a polarization-resolved analysis of Delbr\"uck scattering. Furthermore, we show that the angular distribution of Rayleigh scattering can be used for a highly sensitive determination of the degree and orientation of the linear polarization of the incident hard-x-ray beam, if we rely on the theoretical framework.

Inclination of polarized illumination increases symmetry of structures grown via inorganic phototropism.

Inclination of unpatterned, linearly polarized illumination in the plane of the electric field oscillation effected increased directional feature alignment and decreased off-axis order in Se-Te deposits generated by inorganic phototropic growth relative to that produced using normal incidence. Optically based growth simulations reproduced the experimental results indicating a photonic basis for the morphology change. Modeling of the light scattering at the growth interface revealed that illumination inclination enhances scattering that localizes the optical field along the polarization plane and suppresses cooperativity in defect-driven scattering. Thus, the symmetry of the deposited structures increased as the asymmetry of the illumination increased, as measured by the inclination of the illumination incidence away from the surface normal.

CHANCES OF WRONG INFORMATION RECEPTION DURING ELECTROMAGNETIC INFLUENCE UPON OPTICAL CABLE

Long-distance communication lines are optical fiber lines in most cases now. This moment PM QPSK system (polarization-division multiplex with quadrature phase shift keying) appear. Polarization-division multiplex uses a fact that the optical signal can propagate as two orthogonal polarized modes that allows to use the modes independently and makes it possible to double carrier capacity (together with already other used multiplex system). Two orthogonal waves using in the same fiber can cause problems during lightning discharges close by cable line. Under influence of external cross electrical field (or longitudinal magnetic) the polarizations plane of lights wave can turns on angle, which depends on field value, light path length upon field action and fiber sensitivity. During the influence of external electromagnetic field issue a part of one polarization signal can pass to other orthogonal plane and it will perceive wrongly. The Wavelength Division Multiplexing (WDM) systems development with increasing number of carriers brought to transmission in the same transparency window some tens or hundreds waves. They are shifted relative to each other for some parts of nanometers during the lightning stroke. Therefore the polarization plane rotation will be different for each wave (other conditions being equal): the short waves rotated greater than the long waves. On input of optical amplifier there will be packet of waves with different polarizations, and it can produce problems to filters, optical insulators and amplifiers, to Raman amplifiers specially, which are sensitive to polarization. It is known that short and long waves are moving with different velocity as refraction index depends upon wave length. Usually the rotation angle quantity is small if resistivity of earth near cable is not heavy and if equipment does not contain sensitive to PMD (Polarization Modes Dispersion). This phenomenon passes usually unnoticed. But sometimes with strong thunderstorm and lightning stroke at a short distance the polarization plane rotation can exceed 45º or even 90º. Hereby, it is possible the complex electrical and magnetic fields influence during thunderstorm on orthogonal polarization using, that can lead to additional component appearance in orthogonal axes and to signal reception error. Error level for year is estimated.

Quantum Cryptography Experiment using Optical Devices

The study of quantum cryptography is one of the great interest. A straightforward and reliable quantum experiment is provided in this paper. A half wave plate in linearly polarized light makes up a simplified polarization rotator. The polarization rotates twice as much as the half wave plate's fast axis' angle with the polarization plane when the half wave plate is rotated. Here, an experiment of message sharing is conducted to demonstrate quantum communication between parties. The unitary transformation is performed step by step using half-wave plates represented by the Mueller matrix. A simulation created using Python programming has been used to test the proposed protocol's implementation. Python was chosen because it can mathematically imitate the quantum state of superposition.

Эффект Фарадея в знакопеременном магнитном поле: математическая модель

When creating magnetic focusing systems, for example, for traveling wave lamps, there are known problems associated with the need to adjust the electron flow moving in a given direction along the axis of the device, that is, to align its axis with the magnetic axis of the focusing system. The ideal adjustment of the device is very difficult to achieve due to many influencing factors, therefore, it becomes necessary to create automated complexes for simulating the alignment of the electron beam in the magnetic field formation system for focusing systems. The alignment problems can be solved using magneto-optical methods, since it is known that when exposed to a magnetic field, the light exhibits a number of similar properties (reaction). The aim of the work is to create a mathematical model for the passage of a light beam through an alternating magnetic system based on the Faraday effect. As a result, a mathematical model has been obtained, that should allow modeling the change in the plane of light polarization during the passage (movement of the magneto-optical sensor) along the axis of the magnetic system. The simulation of the passage of light according to the Faraday effect through a magnetic system of one and five magnets is considered.

Efficiency tunable broadband terahertz graphene metasurface for circular polarization anomalous reflection and plane focusing effect

Efficiency tunable broadband terahertz graphene metasurface for circular polarization anomalous reflection and plane focusing effect

ПОЛЯРИЗАТОР НА СЕКТОРНОМУ ХВИЛЕВОДІ, ЧАСТКОВО ЗАПОВНЕНОМУ ДІЕЛЕКТРИКОМ

In the article a polarizer based on a sector waveguide partially filled by dielectric is studied. The design of a polarizer based on a sector waveguide with smaller dimensions of the dielectric plate and a better coefficient of the standing wave rectangular waveguide - polarizer on sector waveguide - rectangular waveguide junction compared with rectangular waveguide-polarizer based on a circular waveguide -rectangular waveguide junction has been developed. The diagrams of the articulateon of the waveguide segments of the antenna-feeder path on rectangular waveguides with a polarizer on a sector waveguide and with a polarizer on a circular waveguide are shown. Formulas for the propagation constant of a sector waveguide partially filled with a dielectric and the effective permittivity of a sector waveguide are given. The dependences of the relative permittivities of a waveguide with a sector dielectric plate parallel and perpendicular to the plane of polarization of the incident wave on the average thickness of the sector dielectric plate are presented. The paper analyzes a sector waveguide partially filled with a dielectric, which has휃=휋/3 и 훷=휋/6. In this case, the scalar eigenfunction of the sector waveguide for the quasi-퐻ଷଵ wave is used. The corresponding dependences of the change in the differential phase shift in the considered wave range on the average thickness of the sector plate are presented. At small thicknesses of the phasing plates the decrease in the polarizer broadband is due to an increase in the phase shift in the long-wavelength part of the range and at large thicknesses in the short-wavelength one. By choosing the permittivity of the material, it is possible to increase the broadband of the polarizer at the expense of some increase in the length of the plate. The dependence of the standing wave coefficient of the junction rectangular waveguide - polarizer - rectangular waveguide on the value 휆/휆଴. The standing wave coefficient for the junction of rectangular waveguide - polarizer on a sector waveguide - rectangular waveguide is 3...5 % less than for a junction of rectangular waveguide - polarizer on a circular waveguide - rectangular waveguide. A polarizer based on a sector waveguide with a dielectric plate has an advantage over a polarizer based on a circular waveguide with a dielectric plate when building antenna-feeder paths on rectangular waveguides. This advantage consists in achieving a lower value of the standing wave coefficient on the waveguide section of the path with a polarizer and a shorter length of the dielectric plate – 1,25휆଴.

Characteristic nuclear spin-induced optical rotation in oxygen-containing organic molecules.

Nuclear spin-induced optical rotation (NSOR) is a nuclear magneto-optic effect that manifests itself as a rotation of the plane of polarization of linearly polarized light. The effect is induced by ordered nuclear magnetic moments within a molecule. NSOR is sensitive to specific, localized interactions. Hence, the connection between the local chemical environment and the corresponding NSOR signal is crucial to understand. Despite the fact that contributions to better understand the connection have been made, the general systematics still remain unknown. In this paper, NSOR in oxygen compounds is investigated systematically to better understand the impact of oxygen atoms on the NSOR signal. NSOR signals are computed using density-functional theory methods for five different classes of oxygen compounds. The ability of NSOR to distinguish different molecules and individual nuclei in the molecules is studied and the information provided by NSOR is compared to conventional NMR spectroscopy. The results reveal that NSOR is capable of chemical distinction between nuclei and molecules, and by using NMR and NSOR together it is possible to distinguish nuclei near the oxygen atom.

Promoted catalytic activity of CO oxidation at low temperatures by tuning ZnO morphology for optimized CuO/ZnO catalysts

Catalytic oxidation of CO is an effective route to eliminate the pollution of automobile exhaust. Tuning the fraction of exposed polar and non-polar crystal facets in ZnO provides an effective strategy to tailor metal-oxide interfacial active sites. Herein, the morphology of ZnO support was tuned to alter the fraction of exposed (002) polar/(100), (101) non-polar facets. ZnO nanodisks and nanorods were prepared, followed by deposition of ∼3.1 ± 0.9 nm CuO nanoparticles. The impact of the ZnO morphology upon CuO deposition and catalytic activity towards CO oxidation were investigated. The CuO/ZnO derived from ZnO nanodisks (NDs) with the most exposed (002) polar plane exhibited more than 2 folds higher catalytic activity at 150 °C than that over CuO/ZnO with commercial ZnO support (CuO/ZnO-C), highlighting the morphology influence of ZnO. For its enhanced catalytic activity and cyclic stability, the CuO/ZnO-NDs could be a promising catalyst for CO oxidation.

Analysis of the accuracy of the signal processing algorithm of the differential phase polarimeter

The purpose of this work is to analyze the effect of the polarimeter signal processing algorithm on the results of measurements of the optical rotation angle of the polarization plane to improve the accuracy of measurements in differential polarimetry. Methods. The paper considers the methods of polarimetry used for the analysis of optically active substances, based on the methods of phase measurements used to calculate the optical rotation angle. The expediency of using the Fourier transform to calculate the phase difference of differential polarimeter signals is noted. To analyze the error of the algorithm, mathematical modeling of the measurement information processing for various signal parameters is applied. Results. The results of the study of the effect of the bit depth of the analog-to-digital converter, the number of samples over the period of the signal and the accumulation time on the accuracy of restoring the phase difference are presented. The influence of the ratio of signal amplitudes and the level of amplitude and phase noise caused by the imperfection of the measuring system has also been investigated. Conclusion. The obtained results make it possible to optimize the operating mode and improve the accuracy of the optical rotation angle measurements using a differential phase polarimeter based on the Fourier transform.

Оптические свойства кристаллов семейства лангасита: La-=SUB=-3-=/SUB=-Ga-=SUB=-5-=/SUB=-SiO-=SUB=-14-=/SUB=-, La-=SUB=-3-=/SUB=-Ga-=SUB=-5.5-=/SUB=-Ta-=SUB=-0.5-=/SUB=-O-=SUB=-14-=/SUB=-, Ca-=SUB=-3-=/SUB=-TaGa-=SUB=-3-=/SUB=-Si-=SUB=-2-=/SUB=-O-=SUB=-14-=/SUB=-

Optical properties of lanthanum-gallium silicate (La3Ga5SiO14), lanthanum-gallium tantalate (La3Ga5.5Ta0.5O14), calcium-tantalum-gallium silicate (Ca3TaGa3Si2O14) crystals in the near ultraviolet (UV) and visible wavelength ranges (200-800 nm) have been studied. For the first time the angles of deviation of the moments of the dipole transition spectral dependences theta(λ) were used to characterize the absorption processes in these crystals. These dependences make it possible to reveal absorption bands that are weakly noticeable on the transmission coefficients spectral dependences, and to estimate the degree of deviation of the dispersion dependence theta(λ) from the value theta=45o corresponding to an ideal ordered crystal. Analysis of theta(λ) dependencies showed that in the studied wavelength range, the lowest deviation from theta =45o is observed in Ca3TaGa3Si2O14, and the highest - in La3Ga5SiO14. The coefficients of the specific rotation angle of the polarization plane rho were obtained by the spectrophotometric interference method in polarized light. The measured values are best approximated by the Vyshin equation. For the first time, dependences of the modified Drude formula 1/rho=f(λ2) were calculated for these crystals. These dependences should be linear in case of an ideal crystal. The largest deviation from the linear dependence is observed for La3Ga5SiO14 crystals, and the lowest for Ca3TaGa3Si2O14. The discrete values of the refractive coefficients No and Ne were measured by the prism method. La3Ga5.5Ta0.5O14 crystals have the highest refractive coefficients, Ca3TaGa3Si2O14 crystals have the lowest. The obtained values are approximated by the Sellmeier equation.

New insights into the photocatalytic mechanism of pristine ZnO nanocrystals: From experiments to DFT calculations

Zinc oxide (ZnO) has been regarded as a promising photocatalytic candidate for the purification of wastewaters containing organic contaminants. In this study, six ZnO nanocrystals with the shapes of granule, flake, rod, porous flake, nanosheet-assembled flower, and nanorod-assembled flower were designed and synthesized to investigate the relationship between their photocatalytic activities and morphological features. All these different morphological samples had high-degree of crystallization and belonged to the hexagonal wurtzite structure of ZnO. The morphology had little effect on the light absorption threshold and band gap of these samples, but showed great effect on their adsorption performance, photocatalytic activity, and separation efficiency of photogenerated electrons and holes. The main reactive radicals generated during the photocatalytic process were O2–, OH, and holes. The theoretical calculations revealed that the polar crystal plane could facilitate the separation of charge carriers. The adsorption and distortion energies for O2 adsorbed onto different crystal planes were found to be much higher than those for H2O. These findings theoretically confirmed why O2– was the dominant group of reactive radicals.

Ultrawideband axion search using a Faraday haloscope

Dark matter is a major constituent of our Universe and the axion is a prime candidate. In this article, it is shown that by exploiting the axion induced magnetization in a magnetic rod and the Faraday effect, axions in the mass range $500--5000\text{ }\text{ }\mathrm{\ensuremath{\mu}}\mathrm{eV}$, a part of which ($>3500\text{ }\text{ }\mathrm{\ensuremath{\mu}}\mathrm{eV}$) is currently inaccessible to experiments, can be searched for using the same experimental setup in a year using the existing technologies. The magnetic rod is placed inside a high-finesse optical cavity, which by confining the probe light inside it increases the interaction time and thus enhances the Faraday effect. This rotates the plane of polarization of the probe light sufficiently and produces a robust signal. Axions of different mass are selected using a dc magnetic field. Detection is carried out by counting photons in the optical domain using a readily available and high quantum efficiency ($\ensuremath{\approx}1$) photon counter in a noise-free environment. An optical interferometric scheme that could provide spectroscopic information about the axion to be searched is also proposed.

Study of the composition of potatoes by agronomic traits determining its suitability for industrial processing

The study of biochemical quality indicators of 26 new potato hybrids was carried out in order to determine the ones mostly suitable for processing into starch and potato products and for use as table variety. An express method was used to determine dry matter (DM), Evers method was used to determine the total starch content of tubers, the polarimetric method and a glucometer test were used to determine reducing sugars, glycoalkaloids and inorganic phosphorus were determined by spectrophotometric method. There have been selected 5 hybrids suitable for industrial processing and as a source material for breeding. One potato hybrid with 25,06 % content of DM, more than 18,22 % of starch met the requirements for potatoes used for processing into starch and starch products; another potato hybrid can be recommended for the production of fried potato products according to the parameters: DM – 22.40 % starch – 16.18 %, reducing sugars – 0.23 %, glycoalkaloids – 62,0 mg/kg. Three of the studied hybrids with the content of DM of more than 22 %, starch not less than 16%, reducing sugars 0.2-0.4 % and glycoalkaloids 60-126 mg / kg may be used for the production of other types of potato products. The rest of the hybrids can only be recommended for use as table potatoes. The relationship between indicators affecting the quality of potato products has been revealed. Correlations were established between the mass fractions of: dry matter and starch in the tuber (r = 0.98) – high correlation; reducing sugars and glycoalkaloids (r = 0.68); tuber dry matter and glycoalkaloids (r = 0.59); dry matter and glucose (r = -0.61); starch and glucose (r = -0.58) – average correlations. It has been established that the mass fraction of reducing sugars and the direction of rotation of the plane of polarization of light by sugars change non-linearly under different temperature conditions of sample storage.

Spectral distribution and flux of [formula omitted]-ray beams produced through Compton scattering of unsynchronized laser and electron beams

Intense, quasi-monochromatic, polarized γ-ray beams with high and tunable energy produced by Compton scattering of laser photons against relativistic electrons are used for fundamental studies and applications. Following a series of photoneutron cross section measurements in the Giant Dipole Resonance (GDR) energy region performed at the NewSUBARU synchrotron radiation facility, we have developed the eliLaBr Monte Carlo simulation code for characterization of the scattered γ-ray photon beams. The code is implemented using Geant4 and is available on the GitHub repository (https://github.com/dan-mihai-filipescu/eliLaBr). Here we report the validation of the eliLaBr code on NewSUBARU LCS γ-ray beam flux and spectral distribution data and two applications performed with it for asymmetric transverse emittance profiles electron beams, characteristic for synchrotrons.The first application is based on a systematic investigation of transverse collimator offsets relative to the laser and electron beam axis. We show that the maximum energy of the LCS γ-ray beam is altered by vertical collimator offsets, where the edge shifts towards lower energies with the increase in the offset.Secondly, using the eliLaBr code, we investigate the effect of the laser polarization plane orientation on the properties of the LCS γ-ray beams produced with asymmetric emittance electron beams. We show that:1. The use of vertically polarized lasers contributes to the preservation of the LCS γ-ray beam maximum energy edge by increasing the precision in the vertical collimator alignment.2. Under identical conditions for the electron and laser beams phase-space distributions, the energy spectrum of the scattered LCS γ-ray beam changes with the laser beam polarization plane orientation. More precisely, the use of vertically polarized laser beams slightly deteriorates the LCS γ-ray beam energy resolution.

Polarimetry of the Total Lunar Eclipse on 2022 November 8

Abstract We have measured the degree of linear polarization of the Moon during its total eclipse on 2022 November 8, and found P ≈ −2% in the V filter. The plane of preferential polarization was oriented at ∼36° counting clockwise from the lunar equator. These measurements suggest global asymmetry in the spatial distribution of aerosol particles in the uppermost atmosphere of Earth, with their net linear polarization being P ≈ −6.5%.

Measuring optical activity with unpolarized light: Ghost polarimetry

Quantifying the optical activity of a sample requires the precise measurement of the rotation of the plane of linear polarization of the transmitted light. Central to this notion is that the sample needs to be exposed to light of a defined polarization state. We show that by using a polarization-entangled photon source we can measure optical activity whilst illuminating a sample with unpolarized light. This not only allows for low light measurement of optical activity but also allows for the analysis of samples that would otherwise be perturbed if subjected to polarized light.

Rotation of the Plane of Polarization of a Three-Dimensional Extremely Short Pulse in an Anisotropic Photonic Crystal Made of Carbon Nanotubes

Rotation of the Plane of Polarization of a Three-Dimensional Extremely Short Pulse in an Anisotropic Photonic Crystal Made of Carbon Nanotubes

Prediction of electronic and optical properties of monoclinic 1T’-phase OsSe2 monolayer using DFT principles

Following the discovery and characterization of transition metal dichalcogenides (TMDs) monolayers, which has created interest in last few years, it would seem natural to explore new possibilities of monolayers. Thus, using the density functional theory (DFT), we investigated the structural, electronic, vibrational and thermodynamic properties, and optical absorption of osmium selenide monolayer (monoclinic 1T’-phase OsSe 2 monolayer). We perform the calculations using the approaches based on the generalized gradient (GGA) and the local density (LDA) approximations for the optimized structure with the minimum energy, as well as we use the hybrid exchange–correlation functional HSE06 recommended in the literature for bandgap energy estimation. An indirect bandgap E g = 0 . 85 eV, E g = 0 . 95 eV and E g = 1 . 80 eV was obtained within the LDA-CAPZ, GGA-PBE and HSE06 level of calculation, respectively. The vibrational normal modes, infrared and Raman spectra were obtained and assigned in the frequency range of 0 − 400 c m − 1 together with the phonon dispersion relation. In addition, the optical absorption was shown to be sensitive to the plane of polarization of the incident light mainly in the range of UV radiation. The thermodynamic potentials and specific heat at constant volume were calculated and analyzed. These results indicated that the monoclinic 1T’-phase OsSe 2 structure could be potentially synthesized and bringing new potential technological applications.

Comparison of Mode Locking Regimes Based on Nonlinear Rotation of the Polarization Plane in Erbium Fiber-Optic Lasers with Dumbbell-Type and Annular Cavity Designs

Comparison of Mode Locking Regimes Based on Nonlinear Rotation of the Polarization Plane in Erbium Fiber-Optic Lasers with Dumbbell-Type and Annular Cavity Designs