Arbitrary Polarization Angle Research Articles

Linear stability of shock waves in ultrarelativistic anisotropic hydrodynamics

Linear stability of a plane shock waves in ultrarelativistic anisotropic hydrodynamics is investigated. The properties of the amplitudes of perturbations of physical quantities are studied depending on the components of the wave vector of a small harmonic perturbation. Analytical calculations for the longitudinal and transverse propagation of shock wave normal with respect to the anisotropy axis (beam-axis) and numerical calculations for an arbitrary polar angle are carried out.

Design of a composite metamaterial toward perfect microwave absorption and excellent load-bearing performance

In this paper, an ultrathin layer of arrayed electromagnetic resonators is introduced on the CFRP laminate to form a meta-CFRP composite. It is quite an exciting and promising design, as the composite metamaterial not only inherits the advantages of the CFRP composite in mechanical performance but can also obtain on-demand microwave absorption properties rather than purely reflective as neat CFRP laminates. Here, several meta-CFRP samples have been prepared by a co-curing process. Near-perfect microwave absorption (i.e., S11 ≤ -10 dB) has been achieved in a series of situations such as under normal incidence and a constant polarization angle, under oblique incidence and an arbitrary polarization angle, and for a relative broadband microwave absorption (11.28 GHz ∼ 12.52 GHz). Moreover, the mechanical properties of the fabricated meta-CFRP samples, including tension, compression, bending, and shear, have also been investigated, which showed an increase of more than 680% compared with previous microwave absorbers. The present work provides a new idea for designing electromagnetic and mechanical dual functional materials, based on which many new materials, for example, strong materials with tunable microwave absorption, can be further developed in the future.

Polarized Radiative Transfer Simulations: A Tutorial Review and Upgrades of the Vector Discrete Ordinate Radiative Transfer Computational Tool

We present an overview and several important upgrades to the Vector Discrete Ordinate Radiative Transfer (VDISORT) code. VDISORT is a polarized (vector) radiative transfer code that can be applied to a wide range of research problems including the Earth’s atmosphere and ocean system. First, a solution is developed to the complex algebraic eigenvalue problem resulting when the b2 component of the Stokes scattering matrix is non-zero. This solution is needed to compute the V component of the Stokes vector I=[I∥,I⊥,U,V]T. Second, a significant improvement in computational efficiency is obtained by reducing the dimension of the algebraic eigenvalue by a factor of 2 resulting in a speed increase of about 23 = 8. Third, an important upgrade of the VDISORT code is obtained by developing and implementing a method to enable output at arbitrary polar angles by the integration of the source function (ISF) method for partially reflecting Lambertian as well as general non-Lambertian surfaces. Fourth, a pseudo-spherical treatment has been implemented to provide important corrections for Earth curvature effects at near horizontal solar zenith and observation (viewing) polar angles. Fifth, a post-processing single-scattering correction procedure has been developed to enhance the accuracy and speed for strongly forward-peaked scattering. With these significant improvements the results from the upgraded version of the VDISORT code match published benchmark results for Rayleigh scattering, Mie scattering, and scattering by non-spherical cirrus particles. The performance of VDISORT for a polarized incident beam source is equally satisfactory. The VDISORT vector radiative transfer code is made public and freely available for use by the growing polarimetric research community including the space-borne polarimeters on the future NASA PACE and AOS missions.

Arbitrary polarization angle and wavefront manipulation of linearly polarized waves using PB phase

In this paper, a novel method for the manipulation of linearly polarized (LP) electromagnetic waves using Pancharatnam–Berry phase is proposed. By combining polarization synthesis and aperture phase distributions, the polarization angle and wavefront of an LP wave can be arbitrarily manipulated. Four metasurfaces were designed and fabricated to generate pencil, vortex, and Bessel beams with different polarization angels, respectively. Simulation and measurement results consist well and demonstrate the proposed method in both polarization and wavefront manipulation.

Optimal weak measurement in the photonic spin Hall effect for arbitrary linear polarization incidence

The photonic spin Hall effect (SHE) has great potential in precision metrology due to its unique spin modulation characteristics. To improve its potential, the effective enhancement of detection precision has become an important issue. In this work, we theoretically and experimentally demonstrate the optimal weak measurement (optimal overlap of pre-selected and post-selected states) with arbitrary linear polarization incidence for both amplified transverse and in-plane shift. Also, based on photonic SHE, a method for arbitrary linear polarization angle detection is then proposed experimentally with a detection accuracy of 0.04 degree. It can provide a guidance for the weak measurement and enlarge the potential application of photonic SHE in field of precision measurement.

Broadband anomalous reflective metasurface for complementary conversion of arbitrary incident polarization angles.

The abrupt phase changes at the interface can modulate the polarization and wavefront of electromagnetic waves, which is the physical mechanism of the plasmonic metasurfaces. Conventional polarization converters are difficult to obtain pure polarized light, and most of the anomalously reflecting metasurfaces are limited by the specific angle of incident polarization. Here, we present a high-efficient polarization-independent metasurface for broadband polarization conversion and anomalous reflection when a plane wave with an arbitrary polarization angle is incident vertically. We vary the dimensions of the polarization conversion unit cells and arrange them periodically to cover the full 2π phase range of cross-polarized light in two orthogonal directions. The simulation results show that the pure anomalous cross-polarization efficiency is over 80% over a wavelength range from 1400nm to 1800nm. In particular, the metasurface can realize the complementary conversion of polarization angle for incident light at any polarization angle, and deflect it to a specific angle. Our design provides strategies for miniaturization and integration of polarization conversion devices and systems.

Vectorial Compound Metapixels for Arbitrary Nonorthogonal Polarization Steganography

Malus' law regulating the intensity of light when passed through a polarizer, forms the solid basis for image steganography based on orthogonal polarizations of light to convey hidden information without adverse perceptions, which underpins important practices in information encryptions, anti-counterfeitings, and security labels. Unfortunately, the restriction to orthogonal states being taken for granted in the common perceptions fails to advance cryptoinformation to upgraded levels of security. By introducing a vectorial compound metapixel design, arbitrary nonorthogonal polarization multiplexing of independent grayscale images with high fidelity and strong concealment is demonstrated. The Jones matrix treatment of compound metapixels consisting of double atoms with tailored in-plane orientation sum and difference allows point-by-point configuring of both the amplitude and polarization rotations of the output beam in an analytical and linear form. With this, both multiplexing two continuous grayscale images in arbitrary nonorthogonal polarization angles and concealing grayscale image on another in an arbitrary disclosure angle window are experimentally demonstrated in the visible TiO2 metasurface platform. The methods shed new light on multifarious metaoptics by harnessing the new degree of freedom and unlock the full potential of metasurface polarization optics.

All-optical wavelength conversion based on dual-polarization SOAs for a 112Gbps PDM-16QAM signal using parallel dual-pump

We demonstrate an all-optical wavelength conversion (AOWC) scheme based on four wave mixing (FWM) effect in dual-polarization semiconductor optical amplifiers (SOAs) for 56Gbps polarization division multiplexing 16-ary quadrature amplitude modulation (PDM-16QAM) signal using parallel dual-pump. The orthogonal dual-polarization SOAs are utilized to improve the optical link capacity in terms of spectrum utilization and bandwidth efficiency. The polarization insensitivity wave signals are obtained at arbitrary polarization angle θ. The wavelength conversion efficiency (CE) is determined by optical signal-to-noise ratio (OSNR), pump spacing, injection current of SOA and pump power. The results show that the bit error rate (BER) of the converted signal 1’ and signal 2’ is lower than the converted signal 1 and signal 2. Our results can be used in long distance fiber optical communications.

All-dielectric ultra-broadband metamaterial absorber based on imidazole ionic liquids

We propose an all-dielectric hollow annular groove ultra-broadband metamaterial absorber (A-D ILMMA) based on imidazole ionic liquids, which is freed of metallic substrate and can offer an extremely wide bandwidth of electromagnetic absorption and prominent wide polarization angle range. When the ionic liquid 1-ethyl-3-methylimidazolium Tetrafluoroborate ([EMIM][BF4]) with a high conductivity and dielectric loss factor is arranged into the hollow annular groove unit cells with a 6 mm total thickness, nearly perfect impedance matching can be achieved in a wide frequency range. Research results show that the simulated absorptivity is over 90% in 13.9–50 GHz with the relative bandwidth of 113%, and the corresponding microwave experiment is performed to support the results of the simulation. Moreover, the A-D ILMMA can work efficiently at arbitrary polarization angles from 0° to 90° and wide incident angles from 0° to 60°.

Modified model of photonic spin Hall effect of Gaussian beam reflected from a dielectric interface

A modified model for the photonic spin Hall effect when a Gaussian beam is reflected from a dielectric interface is derived. Compared with the former models that generally have great limitations (such as only being applicable to p- and s-polarization; or the approximate p-polarization; or invalid around the Brewster angle), the modified model we derived does not have these limitations, which can be suitable for arbitrary linear incident polarization and arbitrary angle of incidence. Furthermore, the modified model is verified by experiments and the experimental results are in good agreement with theoretical results.

Ultra-broadband perfect absorber utilizing refractory materials in metal-insulator composite multilayer stacks.

We present an ultra-broadband perfect absorber composed of metal-insulator composite multilayer (MICM) stacks by placing the insulator-metal-insulator (IMI) grating on the metal-insulator-metal (MIM) film stacks. The absorber shows over 90% absorption spanning between 570 nm and 3539 nm, with an average absorption of 97% under normal incidence. The ultra-broadband perfect absorption characteristics are achieved by the synergy of guided mode resonances (GMRs), localized surface plasmons (LSPs), propagating surface plasmons (PSPs), and cavity modes. The polarization insensitivity is demonstrated by analyzing the absorption performance over arbitrary polarization angles. The ultra-broadband absorption remains more than 80% over a wide incident angle up to 50°, for both transverse electric (TE) and transverse magnetic (TM) modes. The ultra-broadband perfect absorber has tremendous potential for various applications, such as solar thermal energy harvesting, thermoelectrics, and imaging.

Analysis of lateral binding force exerted on multilayered spheres induced by high-order Bessel beams with arbitrary polarization angles

Based on the generalized multi-particle Mie equation (GMM) and Electromagnetic Momentum (EM) theory, the lateral binding force (BF) exerted on multilayered spheres induced by an arbitrary polarized high-order Bessel beam (HOBB) is investigated with particular emphasis on the half-conical angle of the wave number components and the order (or topological charge) of the beam. The illuminating HOBB with arbitrary polarization angle is described in terms of beam shape coefficients (BSCs) within the framework of generalized Lorenz-Mie theories (GLMT). Utilizing the addition theorem of the spherical vector wave functions (SVWFs), the interactive scattering coefficients are derived through the continuous boundary conditions on which the interaction of the multilayered spheres is considered. Numerical results concerning the influences of different parameters of the incident Bessel beam and of the binding body on the lateral BF are displayed in detail. The observed dependence of the separation of optically bound particles on the incidence of HOBB is in agreement with earlier theoretical prediction. Accurate investigation of BF induced by HOBB exerted on multilayered spheres could provide key support for further research on optical binding between more complex multilayered biological cells, which plays an important role in using optical manipulation on stratified particle self-assembly.

Nearly perfect polarization rotation in optical range based on all-dielectric metamaterials

Although using metamaterials in the microwave and terahertz regions has been extensively investigated, the polarization rotation in the optical spectrum with extremely high efficiency and linear tunability for the angle of rotation is still challenging. Here, we report a polarization rotator in the near infrared spectrum using all-dielectric metamaterials with nearly perfect performance. For linear polarization incidences with arbitrary polarization angles, the transmittances are larger than 0.98 and the linear polarizations are still maintained except for a uniform angle of rotation 82°. Thus, with the assistance of a half wave plate, the output polarization angle can be linearly tuned from 0 to 2π. The physical origins are analyzed systematically using a numerical simulation method and Jones calculus. These excellent features give our scheme the potential for all-dielectric integrated polarization rotator related applications at optical range.

Vortex patterns and the critical rotational frequency in rotating dipolar Bose-Einstein condensates

Based on the two-dimensional mean-field equations for pancake-shaped dipolar Bose-Einstein condensates in a rotating frame with both attractive and repulsive dipole-dipole interaction (DDI) as well as arbitrary polarization angle, we study the profiles of the single vortex state and show how the critical rotational frequency change with the s-wave contact interaction strengths, DDI strengths and the polarization angles. In addition, we find numerically that at the `magic angle' $\vartheta=\arccos(\sqrt{3}/3)$, the critical rotational frequency is almost independent of the DDI strength. By numerically solving the dipolar GPE at high rotational speed, we identify different patterns of vortex lattices which strongly depend on the polarization direction. As a result, we undergo a study of vortex lattice structures for the whole regime of polarization direction and find evidence that the vortex lattice orientation tends to be aligned with the direction of the dipoles.

Analytical description of lateral binding force exerted on bi-sphere induced by high-order Bessel beams

Based on the generalized multi-particle Mie equation (GMM) and Electromagnetic Momentum (EM) theory, the lateral binding force (BF) exerted on bi-sphere induced by an arbitrary polarized high-order Bessel beam (HOBB) is investigated with particular emphasis on the half-conical angle of the wave number components and the order (or topological charge) of the beam. The illuminating HOBB with arbitrary polarization angle is described in terms of beam shape coefficients (BSCs) within the framework of generalized Lorenz-Mie theories (GLMT). Utilizing the vector addition theorem of the spherical vector wave functions (SVWFs), the interactive scattering coefficients are derived through the continuous boundary conditions on which the interaction of the bi-sphere is considered. Numerical effects of various parameters such as beam polarization angles, incident wavelengths, particle sizes, material losses and the refractive index, including the cases of weak, moderate, and strong than the surrounding medium are numerically analyzed in detail. The observed dependence of the separation of optically bound particles on the incidence of HOBB is in agreement with earlier theoretical prediction. Accurate investigation of BF induced by HOBB could provide an effective test for further research on BF between more complex particles, which plays an important role in using optical manipulation on particle self-assembly.

Multi-band metamaterial absorber with arbitrary polarization and wide-incident angle

We propose a multi-band metamaterial perfect absorber with a deep-subwavelength thickness and near-unity absorption coefficient at microwave frequencies. This planar metamaterial is composed of periodically arranged concentric metallic rings and a continuous metallic ground plate separated by one or two lossy dielectric layers. The origin of the induced multi-band perfect absorption is attributed to the multiple impedance-matching to free space and can be achieved through tuning the effective constitutive relations by interactions of several electromagnetic resonances. Numerical simulations reveal the electric field and surface current distributions at each absorption peak, and further analysis indicates that the absorption mainly arises from the dielectric loss. Moreover, the absorption could be enhanced and broaden by overlapping the modes of different rings. The absorption is identical for arbitrary polarizations due to the rotational symmetry of the subwavelength unit. It also remains over 90% energy absorption for a wide angle of incidence up to 45 $$^\circ$$ , which is confirmed by the experiment. The designed multi-band absorber is also easy to manufacture by the mature printed circuit board technology, which is favorable for a wide variety of applications.

Strong anisotropic optical conductivity in two-dimensional puckered structures: The role of the Rashba effect

We calculate the optical conductivity of an anisotropic two-dimensional system with Rashba spin-flip excitation within the Kubo formalism. We show that the anisotropic Rashba effect caused by an external field changes significantly the magnitude of the spin splitting. Furthermore, we obtain an analytical expression for the longitudinal optical conductivity associated with inter-band transitions as a function of the frequency for an arbitrary polarization angle. We find that the diagonal components of the optical conductivity tensor are direction-dependent and the spectrum of optical absorption is strongly anisotropic with an absorption window. The height and width of this absorption window are very sensitive to the system anisotropy. While the height of absorption peak increases with increasing effective mass anisotropy ratio, the peak intensity is larger when the light polarization is along the armchair direction. Moreover, the absorption peak width becomes broader as the density of state mass or Rashba interaction is enhanced. These features can be used to determine parameters relevant for spintronics through the optical absorption spectrum.

Triassico: A Sphere Positioning System for Surface Studies with IBA Techniques

We propose here a novel device, called the Triassico, to microscopically study the entire surface of millimeter-sized spheres. The sphere dimensions can be as small as 1mm, and the upper limit defined only by the power and by the mechanical characteristics of the motors used. Three motorized driving rods are arranged so an equilateral triangle is formed by the rod's axes, on such a triangle the sphere sits. Movement is achieved by rotating the rods with precise relative speeds and by exploiting the friction between the sphere and the rods surfaces. The sphere can be held in place by gravity or by an opposing trio of rods. By rotating the rods with specific relative angular velocities, a net torque can be exerted on the sphere which then rotates. No repositioning of the sphere or of the motors is needed to cover the full surface with the investigating tools. An algorithm was developed to position the sphere at any arbitrary polar and azimuthal angle. The algorithm minimizes the number of rotations needed by the rods, in order to efficiently select a particular position on the sphere surface. A prototype Triassico was developed for the National Ignition Facility, of the Lawrence Livermore National Laboratory (Livermore, California, USA), as a sphere manipulation apparatus for ion microbeam analysis at Sandia National Laboratories (Albuquerque, NM, USA) of Xe-doped DT inertial confinement fusion fuel spheres. Other applications span from samples orientation, ball bearing manufacturing, or jewelry.

The solid angle (geometry factor) for a spherical surface source and an arbitrary detector aperture

It is proved that the solid angle (or geometry factor, also called the geometrical efficiency) for a spherically symmetric outward-directed surface source with an arbitrary radius and polar angle distribution and an arbitrary detector aperture is equal to the solid angle for an isotropic point source located at the center of the spherical surface source and the same detector aperture.

Efficient Reciprocity-Based Algorithm to Predict Worst Case Induced Disturbances on Multiconductor Transmission Lines due to Incoming Plane Waves

In this paper, an efficient reciprocity-based algorithm is proposed to predict the worst case voltages and currents induced by external plane waves at the ports of a multiconductor transmission-line system. The proposed algorithm consists of two main steps. In the first step, the far-field radiation of the multiconductor transmission-line system is fully characterized by a minimal number of full-wave simulations. In the second step, this information is used to efficiently evaluate the voltages and currents induced by a plane wave with arbitrary angles of incidence and polarization. After this, their worst case values can be easily found. The main advantage of the proposed algorithm is that no new full-wave simulations are required if different incoming plane waves or different sets of terminations at the ports of the multiconductor transmission-line system are to be considered.