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We study the sharp focusing of the input structured light field that has a non-uniform elliptical polarization: the parameters of the ellipse depend on the position in the input plane (we limited ourselves to the dependence only on the angular variable). Two types of non-uniformity were considered. The first type corresponds to the situation when the semi-axes of the polarization ellipse are fixed while the slope of the major semi-axis changes. The second type is determined by the situation when the slope of the major semi-axis of the polarization ellipse is constant, and the ratio between the semi-axis changes (we limited ourselves to the trigonometric dependence of this ratio on the polar angle). Theoretical and numerical calculations show that in the case of the first type of non-uniformity, if the tilt angle is a multiple of the polar angle with an integer coefficient, then the intensity distribution has rotational symmetry, and the energy flow is radially symmetric and has the negative direction near the optical axis. In this second case, the intensity symmetry is not very pronounced, but with an odd dependence of the ratio of the semi-axes of the polarization ellipse, the focused field at each point has a local linear polarization, despite the rather complex form of the input field. In addition, we investigate the distribution of the longitudinal component of the Poynting vector. The obtained results may be used for the formation of focused light fields with the desired distributions of polarization, Poynting vector density, or spin angular momentum density in the field of laser manipulation and laser matter interaction. [ABSTRACT FROM AUTHOR]

Corrections of the first order of smallness to the vectors of the electromagnetic wave momentum and spin angular momentum densities are obtained in the analytical form in the paraxial approximation for an elliptically polarized incident beam of an arbitrary shape and initial launch angle. These quantities define forces and torques during optical manipulation of micro- and nanoparticles. The corrections in question partially depend on normalized Stokes parameters. They are divided into two groups according to the form of the same-type dependence on three spatial coordinates and the initial launch angle of the beam. A region of the initial launch angles of an elliptically polarized Airy beam is found, which most strongly affect the direction, magnitude, and localization of the central maximum of the corrections. [ABSTRACT FROM AUTHOR]

Keywords: arbitrary polarization; elliptical polarization; optical spin Hall effect; photonic spin Hall effect; spin Hall shift EN arbitrary polarization elliptical polarization optical spin Hall effect photonic spin Hall effect spin Hall shift 2803 2809 7 05/19/22 20220601 NES 220601 1 Introduction The light that is reflected or refracted at an optical interface experiences a microscopic spin-dependent spatial displacement along the perpendicular direction [[1]]. Equation (3) clearly demonstrates that the beam is shifted by HT ht Graph (4)along the I y i -axis. [Extracted from the article]

Elliptically polarized high peak power two‐color lasers have potential applications on material science, biology, optical detection, and terahertz wave generation. Two‐color pulsed lasers with flexible power intensity ratio are essential for analyzing material properties, however, control of power ratio between two lasers is a challenge for developing compact passively Q‐switched (PQS) solid‐state laser. Here, taking advantage of Nd:YAG/Cr4+:YAG composite crystal and a‐cut YVO4 crystal, a PQS Raman microchip laser is developed for generating a two‐color Raman laser with tunable power intensity ratio between two Raman lasers and elliptical polarization. Power intensity ratio tuned from 1 to 0 between 1166 nm Raman laser and 1166/1176 nm two‐color laser is achieved by adjusting a‐cut YVO4 crystalline orientation. State of polarization of Raman laser is elliptical polarization. The ellipticity is flexibly tuned from 0.3 to 0.91 by adjusting pump power and a‐cut YVO4 crystalline orientation. The Raman laser pulses with peak power of 6.4 kW and pulse width of 1.5 ns are obtained. The synchronized Raman laser pulse repetition rate is 14.3 kHz. This work enables development of a compact high peak power two‐color Raman laser with flexible control of power intensity ratio between two color lasers in a diode pumped PQS Raman microchip laser. [ABSTRACT FROM AUTHOR]

The major axis of the elliptically polarized wave generated by a linearly polarized (LP) radiating source and an artificial anisotropic polarizer has been analyzed in this communication. Both theoretical and experimental results show that the major axis of the elliptically polarized wave generated by such a combination has an angle of 0° or 90° to the E-plane of the LP radiator. The angle between the major axis and the E-plane depends on the phase difference of the two orthogonal electric components after propagating through the polarizer. Measurement has been conducted for verification which covered the entire V-band (50–75 GHz). The result in this communication provides instructions for the usage of artificial anisotropic polarizers in detection and measurement, such as the calculation of the polarization efficiency during transmission. [ABSTRACT FROM AUTHOR]

The advancement of laser technology is causing the research field of optics to become more active, and with the help of advancementof technology, more detailed information can be obtained. The primary goal of this work is to calculate differential cross section by using a mathematical model in presence of coulomb potential and elliptically polarized beam with single photon absorption. The developed model shows the differential cross section increases with wavelength and decreases with electron energy with elliptically polarized beam. The differential cross section become maximum at 1.56 radian polarized angle and minimum at -1.56 radian polarized angle. The observation is based on 1.5eV laser photon energy, laser field intensity 1014Wcm-2, polarized angle 1.56 radian angle, and electron energy 0 to 600eV. Using the born first approximation and the Volkov wave function, the developed equation is obtained. The numerically obtained differential crosssection in this work is approximately 10-19m²to 10-20m², which is less than the differential cross section obtained by Flegel et al. (2013), which is approximately 10-17m². [ABSTRACT FROM AUTHOR]

Polarization control of dual‐wavelength high peak power Raman lasers based on passively Q‐switched technology and yttrium vanadate (YVO4) crystal are widely used for generating novel laser sources, terahertz wave, material processing, and manipulating microparticles. However, the Raman lasers are usually linear polarization. Here, elliptical polarizations with controllable ellipticity and azimuthal angle are manipulated by adjusting the crystalline orientation of a‐cut YVO4 crystal in a passively Q‐switched Raman laser constructed with a Cr4+,Nd3+:Y3Al5O12 (Cr,Nd:YAG) crystal and a a‐cut YVO4 crystal. The ellipticity of the elliptically polarized dual‐wavelength Raman laser varies in a sinusoid modulation as a‐cut YVO4 crystal rotates with respect to the major axis of the intracavity fundamental laser and increases with applied pump power. The azimuthal angle varies in the same speed as a‐cut YVO4 crystal rotates. Anisotropic behavior of sinusoidal modulation of output power, pulse energy, and peak power is observed as a‐cut YVO4 crystal rotates. There are four peaks and four troughs for ellipticity, output power, pulse energy, and peak power within a 360° rotation of a‐cut YVO4 crystal. This work provides a solid and simple method for developing elliptical polarization controllable dual‐wavelength passively Q‐switched Raman laser with high peak power for various potential applications. [ABSTRACT FROM AUTHOR]

High cross-polarization isolation (CPI) is crucial to the accurate polarization measurement using polarimetric phased array radar (PPAR). In this article, we propose an adaptive direction-dependent polarization state configuration (AD2PSC) method to improve the polarization isolation. Compared with the conventional fixed polarization state of radiated wave whether it is linear, circular, or elliptical polarization state, our AD2PSC approach configures the polarization state on basis of beam steering. To achieve the adaptive configuration of magnitude and phase of the dual-polarization antenna, an improved steepest descent algorithm is put forward. To facilitate the uniform representation for the polarization measurement application of PPAR, the universal expressions of intrinsic and measured backscatter matrices are derived for arbitrary polarization state. The dual-polarization dipole array is used to assess the priority of our proposed method. Compared with the conventional approaches, our approach could obtain higher CPI while being available for a larger scanning range. The configured CPI meets the specific polarization requirement for PPAR. [ABSTRACT FROM AUTHOR]

Solitons are prevalent in various nonlinear physical systems. Optical solitons in optical fibers are exceptionally intriguing due to the multitude of both linear and nonlinear optical effects that are involved during their propagation. Here we demonstrate elliptically-polarized soliton self-frequency shift (SSFS) in a novel isotropic fiber, photonic-crystal (PC) rod. We combine three methodologies, i.e., experimental, numerical, and analytical, to elucidate the fundamental aspects of this novel physical process. Our results show that wavelength-shifted, elliptically-polarized solitons can be generated through the elliptically-polarized SSFS in PC rod. Our research sheds new light on the soliton physics. [ABSTRACT FROM AUTHOR]

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The design and development technique for the enhancement of bandwidth and gain using biodegradable star‐shaped dielectric resonator antenna (SDRA) electrified by two cross‐coupled apertures for broadband applications is presented in this article. The SDRA is fabricated using biodegradable PLA, which is a special type of polymer and made from renewable resources instead of nonrenewable petroleum‐based resources using additive manufacturing technique. Broad bandwidth of 37% is achieved by modifying rectangular dielectric resonator antenna with feeding it by two apertures (slots) of unequal length to excite different modes. The combination of the circular‐shaped split‐ring resonator has been used as a metamaterial for gain enhancement, which enhanced the maximum gain of the antenna by ∼5.4 dB (82.7%). The computed average efficiency within the operating band is ∼80.51%. The proposed antenna is circularly polarized at 5.8 GHz. The proposed antenna fulfills the bandwidth requirements for the IEEE 802.11a WLAN standards (5.15‐5.35 and 5.725‐5.825 GHz), and it is also suitable for various other applications such as satellite navigation systems, aeronautical and meteorological radio navigation services in C‐band. [ABSTRACT FROM AUTHOR]

Electromagnetic ion cyclotron (EMIC) waves have long been considered major plasma waves that can cause the atmospheric precipitation of electrons. In this work, we perform test particle calculations of the interactions between relativistic electrons and EMIC waves with oblique wave normal angle (WNA) and noncircular polarization. We demonstrate advective and diffusive changes in electron pitch angle (PA) under a uniform background magnetic field for broad ranges of kinetic energy (KE), PA, WNA, and ellipticity. First, we find that the direction of advective PA changes can be of either sign, being positive (negative) for a lower (higher) initial PA. Second, an oblique WNA can enhance the advection effects on PA changes, particularly for KE ~2.5–4 MeV and a broad range of initial PAs. In contrast, a more linear polarization can decrease advection for a broad range of KE and initial PAs. Third, phase space trajectories depend strongly on specific values of WNA, ellipticity, KE, and PA. Sometimes a phase‐averaged PA change is a net result of a time‐dependent mixture of the phase trapping, untrapping, and bunching effects. Lastly, the overall effect of finite WNA and ellipticity on diffusive PA changes is less systematic than on advection. Nevertheless, we identify a range of KE and PA where the diffusion tends to increase for a larger WNA and decrease for a more linear polarization. The results in this work emphasize a strong necessity for incorporating precise information on WNA and ellipticity into evaluations of electron scattering by EMIC waves. Key Points: Finite wave normal angle (WNA) and ellipticity of EMIC waves strongly affect pitch angle changes of relativistic electronsElectron phase space trajectories are highly dependent on WNA and ellipticity, sometimes exhibiting complex and time‐dependent featuresAll these effects are sensitively dependent on initial kinetic energy and pitch angle of electrons [ABSTRACT FROM AUTHOR]

Polarization of tri-axial signals is defined using instantaneous rotational characteristics of the three-dimensional (3D) trajectory. We propose a rotational model to parameterize the time evolution of the 3D trajectory as a sequence of scaled rotations. Using this model, the velocity-to-rotation transform is defined to estimate the eigenangle, eigenaxis and orientation quaternion that quantify the instantaneous rotational parameters of the trajectory. These rotational parameters correspond to p-dimensional directional random vectors (DRVs). We propose two approaches to discriminate between the presence and absence of an elliptically polarized trajectory generated by human footsteps. In the first approach, we fit a von Mises-Fisher probability density function to the DRVs and estimate the concentration parameter. In the second approach, we employ the Kullback-Leibler divergence between the estimated nonparametric hyperspherical probability densities. The detection performance of the proposed metrics is shown to achieve an accuracy of 97% compared to existing approaches of 82% for footstep signals. [ABSTRACT FROM AUTHOR]

The Stoneley problem is analytically solved for the piezoheterolayers of cubic symmetry crystals for the first time. New types of acoustoelectric waves, in contrast to classical Stoneley waves, are plane-polarized in the direction orthogonal to the sagittal plane. The wave electric field in each layer is elliptically polarized in the sagittal plane. The use of new types of acoustoelectric waves will make it possible to significantly extend the capability of modern acoustoelectronic devices and is directly associated with the transition from acoustoelectronics to acoustonanoelectronics corresponding to the nanometer wavelength range with a carrier frequency of the order of hundreds of gigahertz. [ABSTRACT FROM AUTHOR]

A new but yet well proven way of making elliptically polarized dipole radiation from the BESSY II storage ring applicable to the SX700-type collimated plane-grating monochromator PM3 is described. It is shown that due to the limited vertical acceptance of the grating a simple use of vertical apertures is not possible in this case. Rather, deflecting the beam upwards or downwards by rotating the vertically collimating toroidal mirror M1 around the light axis leads to excellent performance. The resulting detuning of the photon energy can be taken into account by a readjustment of the monochromator internal plane mirror M2. The energy resolution of the beamline is not affected by the non-zero `roll' of the collimating mirror. [ABSTRACT FROM AUTHOR]

The gain bandwidth constraint of sequential-rotation arrays (SRAs) has been an open issue since it was first pointed out in 1989. This paper reveals the reason, provides some useful conclusions and proposes an optimum design. Firstly, a first-order analytical formula is derived for the array factor (AF) of the 4-element sub-SRA. The formula embraces the polarization properties of the antenna elements. The AF is found to be dependent on the elements' polarization properties and frequency, which is not found in conventional regular arrays. Based on the theoretical results and full-wave simulations, these dependencies are analyzed in detail. Secondly, an optimum design is proposed to enhance the gain bandwidth: to constitute SRA with elliptically polarized elements (this type of SRA is denoted as EP-SRA) rather than the conventional circularly polarized elements (this type of SRA is denoted as CP-SRA). Detailed design guidance is presented for this new method. Finally, as an example, a CP-SRA and an EP-SRA are designed and tested for comparison. According to the example, by employing EP-SRA, the 1 dB AF bandwidth is improved by 80%, the measured 1 dB/3 dB gain bandwidth is enhanced by 114%/76%. In fact, the conventional CP-SRA and LP-SRA (SRA with linearly polarized elements) are two special cases of the proposed EP-SRA. [ABSTRACT FROM PUBLISHER]

ABSTRACT In recent years, polarization agility in single antenna is most desired characteristic in different applications. In this article, a microstrip antenna with new triple-polarization diversity is designed and developed for C-band pulsed altimeter used in many of the missile/aerospace application. The achieved polarization includes elliptical polarization, circular polarization (CP), and linear polarization. The antenna can be biased to get either right-handed circular polarization (RHCP) or left-handed circular polarization (LHCP). The antenna consists of a rectangular patch, four PIN diodes and two feeding lines along vertical and horizontal edge of the antenna. The necessary biasing network also embedded in the antenna circuit. Four PIN diodes are used for the polarization diversification and controlled by +5V external DC power supply. A prototype of the antenna has been fabricated and tested. Simulated results are in agreement with experimental data. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1348-1353, 2014 [ABSTRACT FROM AUTHOR]

We report experimental and simulation studies of the effect of interconnects on the polarization characteristics of nanoscale dipole antennas. In the long-wave infrared (LWIR) regime, isolation of the postdetection dc circuit and the optical-frequency antenna currents is difficult because the wavelength of the incident radiation is comparable to the dimensions of the isolating elements, and because metal and dielectric losses limit the quality factor of reactive elements at LWIR frequencies. Thus, these “dc” interconnects can also contribute to the radiation pattern of the antenna, and affect the polarization characteristics of the antenna. Antenna-coupled metal–oxide–metal diodes (ACMOMD) based on planar half-wave dipole antennas with different detector read-out interconnectgeometries are fabricated adjacent to each other on the same die. ACMOMDs with geometrically-different read-out interconnects have different associated polarization ellipses. 3-D, full-wave simulations in Ansoft high-frequency structure simulator (HFSS) are performed to obtain the polarization tilt angles for different read-out interconnect geometries. The relative shifts in polarization axes are measured experimentally and compared to the relative tilt angles of the polarization ellipses obtained through simulations. The simulated relative shifts in the polarization axes are in good agreement with the measured values. [ABSTRACT FROM PUBLISHER]

Currently, surface nuclear magnetic resonance (SNMR) method is the only geophysical method that detects groundwater directly. In this paper, we investigate the effect of elliptical polarization in the perpendicular excitation magnetic field. The effect of elliptical polarization is clearly visible in our ellipticity calculation and it can cause strong distortion to the excitation field in the presence of high subsurface conductivities. By examining the co-rotating and counter-rotating components of the field, we show that elliptical polarization affects transmitting and receiving processes differently and that a clear phase lag exists between transmitter loop and receiver loop. Finally, we derive the response function of coincident loops and calculate proton tip angles, the kernel function and SNMR response curves of a 1D aquifer model. Based on the simulations, we conclude that the elliptical polarization and phase lag can significantly affect SNMR response and it is essential to include elliptical polarization in SNMR modeling and data interpretation. [ABSTRACT FROM AUTHOR]

A new leaky-wave antenna based on substrate integrated waveguide (SIW) with H-shaped slots is proposed and investigated. The SIW with H-shaped slots is analyzed as a rectangular waveguide with H-shaped slots. Using an aperture magnetic field integral equation (MFIE), it is found that the SIW with H-shaped slots supports a leaky waveguide mode, a surface-wave mode and a proper waveguide mode depending on frequency. The radiation property is also evaluated using the MFIE. The leaky-wave antenna based on the SIW with H-shaped slots has a narrow beam that scans from broadside to endfire with frequency. The antenna produces an elliptical polarization, including circular polarization. Measured results are consistent with the simulation from HFSS and the theoretical analysis from the MFIE. [ABSTRACT FROM PUBLISHER]

One hundred years ago Michelson discovered circular polarization in reflection from beetles. Today a novel Mueller-matrix ellipsometry setup allows unprecedented detailed characterization of the beetles' polarization properties. A formalism based on elliptical polarization for description of reflection from scarab beetles is here proposed and examples are given on four beetles of different character: Coptomia laevis – a simple dielectric mirror; Cetonia aurata – a left-hand narrow-band elliptical polarizer; Anoplognathus aureus – a broad-band elliptical polarizer; and Chrysina argenteola – a left-hand polarizer for visible light at small angles, whereas for larger angles, red reflected light is right-handed polarized. We confirm the conclusion of previous studies which showed that a detailed quantification of ellipticity and degree of polarization of cuticle reflection can be performed instead of only determining whether reflections are circularly polarized or not. We additionally investigate reflection as a function of incidence angle. This provides much richer information for understanding the behaviour of beetles and for structural analysis. [ABSTRACT FROM AUTHOR]

Based on a developed and experimentally tested model, self-oscillatory lasing regimes have been studied for a Class A four-frequency gas ring laser with linear coupling of elliptically polarized counter-propagating waves. In the self-oscillatory regime, switching of the intensities, polarization states, and phase differences of the counter-propagating waves is observed, and also a polarization-phase dynamics effect involving displacement of the intensity switching point (with respect to detuning), due to the phase shift as a result of an ellipticity different from zero. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to present new special explicit inhomogeneous plane wave solutions of the linearized equations of motion for elastic cubic crystals. It is based upon the “directional-ellipse” method which leads to an eigenvalue problem for the complex symmetric acoustical tensor. The solutions are obtained by considering a special case for which the determination of the three complex eigenvalues of this tensor reduces to finding the three complex cubic roots of a real positive number. Explicit simple expressions are presented for the slowness and amplitude bivectors. [ABSTRACT FROM AUTHOR]

It is proved that elliptically polarized finite-amplitude inhomogeneous plane waves may not propagate in an elastic material subject to the constraint of incompressibility. The waves considered are harmonic in time and exponentially attenuated in a direction distinct from the direction of propagation. The result holds whether the material is stress-free or homogeneously deformed. [ABSTRACT FROM AUTHOR]

It is highly desirable to design optical devices with diverse optomechanical functions. Here, we investigate lateral optical force exerted on subwavelength-diameter (SD) optical fibers harnessed by input light modes with different polarizations. It is interesting to find that input light modes of circular or elliptical polarizations would bring about lateral optical force in new directions, which has not been observed in previous studies. By means of finite-difference time-domain (FDTD) simulations, detailed spatial distributions of the asymmetric transverse force density are revealed, meanwhile dependence of optical force on input light polarizations, fiber diameters, and inclination angles of fiber endfaces are all carefully discussed. It is believed that polarization-sensitive reflection, refraction, and diffraction of optical fields occur at the interface, i.e., fiber oblique endfaces, resulting in asymmetrically distributed optical fields and thereafter non-zero transverse optical force. We believe our new findings could be helpful for constructing future steerable optomechanical devices with more flexibility. [ABSTRACT FROM AUTHOR]

The differential cross section for one-photon molecular detachment by an elliptically polarized field is analyzed for a one-electron molecular model comprised of an electron in the field of two (generally nonequivalent) attractive zero-range potentials (ZRPs) separated by the distance. A phenomenological parametrization of the photodetachment cross section for a fixed-in-space molecular system in terms of two scalar dynamical parameters is presented and circular dichroism effects are discussed. Analytic results for the dynamical molecular parameters within the ZRP molecular model are used to analyze interference phenomena (including two-center interference) and dichroic effects in the detached electron angular distributions and their dependence on the interatomic distanceand on the orientation of the molecular axis with respect to the polarization plane. Numerical ZRP results for angular distributions are presented for both symmetric and asymmetric molecules in an elliptically polarized field. [ABSTRACT FROM PUBLISHER]