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The holographic interference of either same‐handed or orthogonal polarized beams is commonly employed in the fabrication of optical elements as it enables the development of an ideal sinusoidal surface modulation by inducing the mass migration of photochromic polymer. However, this approach encounters challenges in producing multiplexed optical elements with a complex surface topography, primarily due to only sinusoidal surface topography which limits control over the feature's shape and size. Here, a versatile approach is demonstrated for fabricating spatially multiplexed optical elements using ellipticity‐controlled orthogonally elliptically polarized (OEP) beams that offer distorted square‐like and rhombus‐like pillars on the azopolymer layer by asymmetric azopolymer migration driven by spatially varying ellipticity and azimuth angle of interference beam. These multiplexed distorted shapes enable selective energy transfer during light diffraction and also induce a π/8$\pi /8$ phase‐shift to polarization states. Ellipticity control of both writing and interference beams provides an additional degree of freedom for structuring the surface topography of optical elements. Furthermore, a quantitative analysis of the multiplexed OEP surface relief is performed to achieve distinct diffraction properties, thereby rendering its suitability for fabricating complex optical elements. [ABSTRACT FROM AUTHOR]

Background. Polaritons attract the attention of researchers and engineers with their unique properties and promising applications in the field of micro- and nanoelectronics. Such applications could include devices such as transistors or even polaritons lasers, as have been reported in the scientific literature. Aim. The work analyzes the frequency reflection spectra upon excitation of polaritons, and also considers the change in the polarization ellipse upon reflection of circularly polarized light from an anisotropic crystal. Methods. Based on the wave equation in an anisotropic medium, a dispersion equation for polaritons is derived. To calculate energy reflection coefficients using the characteristic matrix method. Results. An aluminum nitride AlN crystal was chosen as the object of analysis. It is shown that the use of circularly polarized incident radiation makes it possible, using an anisotropic crystal, to change the nature of polarization from circular to almost linear polarization. Conclusion. The found dependence of the polarization of reflected light can be used in electronic devices based on polaritons.

The paper proposes a novel procedure and the corresponding mathematical method to measure the polarization characteristics of a planar wave. The method is intended and described as a method for measurement of an antenna of unknown polarization using dipole-like linearly polarized antenna in far field zone of the measured antenna. The procedure consists of only three amplitude measurements using the linear-polarized antenna in three positions, followed by a specific mathematical transformation of the obtained values into polarization parameters – axial ratio and polarization ellipse main axis tilt angle. This mathematical transformation is one of the key contributions of the presented work. It is based on the decomposition of a wave into two circularly polarized waves and on the representation of the electric field as a vector whose components are complex numbers. Furthermore, the novelty of the proposed method is that only three measurements taken at arbitrary angles of the measuring antenna are sufficient to calculate the polarization ellipse parameters. This can have practical advantages, since this method does not require expensive phase measurements and lengthy phase calibrations. If beside axial ratio and polarization ellipse tilt angle also the sense of elliptical polarization is of interest, a simple supplement method is suggested. A potential impact of noise and interference presence during measurements on the applicability of the method in certain cases is thoroughly explained. A supplement method is needed in some of such cases which is explained in detail and the appropriate procedure given.

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]

The spin Hall effect of light (SHEL) is the microscopic spin-dependent splitting of light at an optical interface. Whereas the spin Hall shift under linearly polarized light is well-formulated, studies on the SHEL under elliptically or circularly polarized light have primarily relied on numerical computation. In this work, an explicit analytic formula for the spin Hall shift is derived under arbitrarily polarized incidence. Furthermore, from this explicit expression, we demonstrate that the spin Hall shift can be enhanced at any incident angle by using polarization degree of freedom and is independent of the Fresnel coefficients of an interface under circularly polarized light. The analytic formula will help us understand the SHEL under general polarization intuitively and realize unprecedented modulation of the SHEL.

Within the framework of electroweak theory, we investigate the elastic scattering process e−+νμ→e−+νμ in the presence of an intense elliptically polarized laser field. We derive an analytical expression for the spin-unpolarized differential cross section using the first Born approximation and the Dirac-Volkov states to describe the incident and scattered electrons. Our results generalize those found for the linearly polarized field by Bai et al. (2012) [24] and for the circularly polarized field by El Asri et al. (2021) [23]. We find that the differential cross section is significantly enhanced for linear polarization and reduced for circular and elliptical polarizations.

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.

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]

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]

We consider the solution of the equation of motion of a classical/quantum spin subject to a monochromatical, elliptically polarized external field. The classical Rabi problem can be reduced to third-order differential equations with polynomial coefficients and hence solved in terms of power series in close analogy to the confluent Heun equation occurring for linear polarization. Application of Floquet theory yields physically interesting quantities like the quasienergy as a function of the problem's parameters and expressions for the Bloch–Siegert shift of resonance frequencies. Various limit cases are thoroughly investigated. [ABSTRACT FROM AUTHOR]

• Nanosecond dual-pulse Raman lasers with tunable pulse interval from 36.3 ns to 63.1 ns have been obtained. • Elliptically polarized dual-pulse Raman lasers with ellipticity tunable from 0.08 to 0.54 are achieved by adjusting pump power. • Dual-pulse Raman laser with pulse interval of 40.2 ns and equal peak power of 1.7 kW has been achieved. Dual-pulse solid state lasers with pulse interval of tens nanoseconds have been applied in laser-induced breakdown spectroscopy, laser drilling, medical treatment, and atmospheric monitoring. Here, a Yb:YAG/Cr4+:YAG/YVO 4 passively Q-switched Raman laser has been developed for generating dual-pulse lasers with tunable pulse interval and elliptical polarization. Pulse interval and pulse amplitude ratio between peaks of satellite pulse and main pulse are controlled by adjusting the incident pump power (P in). As P in increases from 1.3 to 5.9 W, the pulse interval decreases from 63.1 to 36.3 ns, and the pulse amplitude ratio between peaks of satellite pulse and main pulse increases from 0.1 to 1.1 for dual-pulse Raman lasers. At P in = 4.9 W, dual-pulse Raman laser with equal peak power of 1.7 kW and pulse interval of 40.2 ns is obtained. The pulse widths are 2.7 and 3.6 ns, and the pulse energy are 4.6 and 6.2 μJ for the main pulse and satellite pulse, respectively. The elliptical polarization with ellipticity tunable from 0.08 to 0.54 is obtained for dual-pulse passively Q-switched Raman laser as P in increases. Such a nanosecond dual-pulse laser source has the potential to expand simple, compact portable and economical laser applications in various fields. [ABSTRACT FROM AUTHOR]

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]

Abstract The strong effect that beam polarization has on the performance of industrial laser cutting is well known. The linear and circular polarization states were widely investigated for CO 2 lasers. These two states are, in fact, special cases of elliptically polarized laser beams. Theoretical models have predicted an optimal cutting performance for a specific ellipse ratio (b/a = 0,75), but experimental validation was never reported. The main reason is that this characteristic is difficult to obtain in practice. With the technology shift towards solid state lasers, different optical solutions become available for polarization control of high power laser beams (e.g. transmissive beam retarders). This paper reports on the novel design of an elliptically polarized laser beam with a continuous control of the ellipse axes ratio. Starting with a full description of the concept, the equations describing the control of the optical elements are deduced using Jones calculus formalism. A motorized optical module has been built to transform the output of a linearly polarized laser beam into a given elliptic polarization characteristic. Beam analysis equipment was used to validate the experimental setup. Cutting experiments were realized for 2 mm thick 304 L stainless steel and compared with a simulation model. Both results show a comparable nonlinear effect on the achievable maximum cutting speed. The influence of the beam shape is also considered, revealing a strong interaction with the beam polarization. With the help of simulation tools, the applicability of such concept is investigated and, in agreement with the experimental results, the obtained output confirms that the optimal ellipse beam ratio is much closer to b / a = 0 than anticipated in literature. [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]

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.

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]

In the framework of the continuum approach we study the behavior of the orientational structure of a ferronematic liquid crystal with soft planar coupling between the liquid crystal matrix and magnetic particles in an elliptically polarized rotating magnetic field. We reveal synchronous and asynchronous oscillating regimes of orientational structure rotation for unbounded sample. We obtain the dependence of the critical angular velocity, which determines the boundary of regimes, on suspension parameters and the magnetic field for different values of its ellipticity. We show that transitions between the regimes are induced by the change in the coupling energy, the ellipticity parameter, the angular velocity, and the magnetic field. We find out that the critical angular velocity of an elliptically polarized magnetic field is always less than the critical velocity of a circularly polarized field. We analyze the stability thresholds of the orientational rotation regimes of a ferronematic liquid crystal and a nematic without magnetic admixture depending on the ellipticity of the magnetic field. We show that the presence of the magnetic particles increases the stability threshold of a synchronous oscillating regime of the suspension rotation. [ABSTRACT FROM AUTHOR]

An elliptically polarized electromagnetic wave transports linear and angular momentums, and exerts force and torque on an exposed surface. The angular momentums associated with the left- ( L ) and right-handed ( R ) circularly polarized waves are parallel and opposite to the direction of propagation, respectively. Applying the principle of superposition, an algorithm is constructed to decompose the elliptically polarized wave into L - and R -components. The relationship between the resultant angular momentum and the electrical energy of the elliptically polarized wave is completely determined by Stokes parameters. Utilizing the proposed relation to study the propagation of the polarized wave through an anisotropic crystal, it is found that the angular momentum brings the ordinary and the extraordinary waves to produce self-modulation effect, working as a pilot wave, or a hidden-variable, as suggested by de Broglie and Bohm. [ABSTRACT FROM AUTHOR]