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Light beams possess various dimensions, such as wavelength, spin angular momentum (SAM), and orbital angular momentum (OAM), which are indispensable in numerous optical applications. However, traditional techniques entail multiple attempts to disclose desired optical information, utilizing unwieldy multi‐pass systems or mechanically moving parts that are cumbersome to integrate into compact and integrated optical systems. Here, a single‐layer dielectric metasurface platform is proposed that enables multi‐dimensional demultiplexing and decoding, circumventing the need for conventional bulk optical elements. The platform can demultiplex 3D light parameters (wavelength, SAM, and OAM) and focus them at distinct spatial positions on a designated focal plane, providing a superior alternative to far‐field beams for integration with optical fiber and communication chips. The study verifies 132‐bit independent channels for a multi‐dimensional demultiplexer and demonstrates the metasurface‐based component's ability to function as an elliptic polarization decoder through a 4‐bit elliptic polarization coding transmission experiment. This work provides a compact and efficient platform for demultiplexing multi‐dimensional SAM and OAM states over a broad wavelength range, with potential implications for optical communications, optical data storage, optical information encryption, and quantum information sciences. [ABSTRACT FROM AUTHOR]

• Elastic spin is explicitly derived and experimentally observed for all basic modes in rods. • Unidirectional wave routing is observed due to spin-momentum coupling. • Asymmetric transmission of longitudinal mode requires extremely elliptical chiral source. • Spin-momentum coupling of torsional mode depends on cross-section warping effect. The unusual topology of elastic waves in continuum systems has been recently uncovered. Prominently, the spin of Rayleigh-Lamb waves has been experimentally observed and used to achieve the unidirectional wave propagation. In this work, the elastic wave spin in thin rod systems is theoretically predicted and experimentally observed, for all the three basic wave modes, i.e., the zero-order flexural, longitudinal and torsional modes. By elaborately building up the subwavelength chiral sources, the spin-momentum locking has been achieved for these three modes within broad frequency range. Interestingly and surprisingly, the spin-momentum locking occurs for flexural and longitudinal modes in both circular and non-circular thin rods; the spin-momentum locking for torsional modes only exits in non-circular thin rods, due to the warping effect in non-circular cross-section rods. Our results open up the door for elastic wave spin in thin rod systems, and provide general tips for the research on basic modes in diverse thin rods, based on either the continuum media or the artificial metamaterials in future. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Generation of magneto-optic effects by the interaction of the CMB with cosmic magnetic fields is studied. Effects which generate polarization such as the Cotton–Mouton effect, vacuum polarization and photon–pseudoscalar mixing in external magnetic field are studied. Considering the CMB linearly polarized at decoupling time, it is shown that photon–pseudoscalar mixing in external magnetic field, the Cotton–Mouton effect in plasma and the vacuum polarization in cosmic magnetic field, would generate elliptic polarization of the CMB depending on the photon frequency and magnetic field strength. Among standard magneto-optic effects, the Cotton–Mouton effect in plasma turns out to be the dominant effect in the generation of CMB elliptic polarization in the low frequency part ν 0 ∼ 10 8 – 10 9 Hz with degree of circular polarization P C (T 0) ≃ 10 − 10 – 10 − 6 for magnetic field amplitude B e 0 ∼ 1 nG – 100 nG. The vacuum polarization in magnetic field is the dominant process in the high frequency part ν 0 ≥ 10 10 Hz where the degree of circular polarization at present is P C (T 0) ≲ 10 − 11 in the best scenario. The effect of pseudoscalar particles on the CMB polarization is also studied. It is shown that photon–pseudoscalar particle mixing in cosmic magnetic field generates elliptic polarization of the CMB as well and even in the case of initially unpolarized CMB. New limits/constraints on the pseudoscalar parameter space are found. By using current limit on the degree of circular polarization of the CMB, the upper limit of | g ϕ γ | < 4.29 × 10 − 19 (G / B e 0) GeV − 1 for m ϕ < 1.6 × 10 − 14 eV in the weak mixing case is found. If | g ϕ γ | < 1.17 × 10 − 24 (G / B e 0) GeV − 1 , a value of the order | g ϕ γ | ≃ 10 − 26 (G / B e 0) GeV − 1 for m ϕ ≃ 1.6 × 10 − 14 eV in the resonant case, from large scale temperature anisotropy is obtained. Prior decoupling CMB polarization due to pseudoscalar particles is also discussed. [ABSTRACT FROM AUTHOR]

A new dual-polarized 3-D frequency-selective surface (FSS) with quasi-elliptic bandpass response is proposed by virtue of the square coaxial waveguide (SCW). By utilizing the SCW as one propagation path in the unit cell, two resonators can be generated intrinsically without introducing any extra structures. In addition, the parallel-plate waveguide constructed by sandwiching the ABS frame between outer conductors of adjacent SCWs will provide a second propagation path and create another resonator. With the help of these resonators, a passband with two transmission poles can be obtained. Furthermore, there are two finite transmission zeros locating at both sides of the passband due to the fact that the signals passing through these two propagation paths are combined out of phase, leading to both-sided sharp roll-off skirt. The E-field analysis and equivalent circuit model presented offer a physical insight into the operating principle of the proposed 3-D FSS. For the purpose of validation, the FSS is fabricated through the 3-D printing technique. The measured results exhibit high frequency selectivity, dual polarizations, and stable bandpass response under a variation of the incidence angle. [ABSTRACT FROM PUBLISHER]

An exact analytical expression is obtained for the orbital angular momentum (OAM) of a Gaussian optical vortex with a different degree of ellipticity. The OAM turned out to be proportional to the ratio of two Legendre polynomials of adjoining orders. It is shown that if an elliptical optical vortex is embedded into the center of the waist of a circularly symmetrical Gaussian beam, then the normalized OAM of such laser beam is fractional and it does not exceed the topological charge n . If, on the contrary, a circularly symmetrical optical vortex is embedded into the center of the waist of an elliptical Gaussian beam, then the OAM is equal to n . If the optical vortex and the Gaussian beam have the same (or matched) ellipticity degree, then the OAM of the laser beam is greater than n . Continuous varying of the OAM of a laser beam by varying its ellipticity degree can be used in optical trapping for accelerated motion of microscopic particles along an elliptical trajectory as well as in quantum informatics for detecting OAM-entangled photons. [ABSTRACT FROM AUTHOR]

A theoretical model of NAREX (non-adiabatic rotational excitation) and field-free molecular orientation by a short specific elliptically polarised laser pulses (EPLPs) driving a polar molecule is presented. By choosing the proper value of elliptically polarised field parameters, efficient field-free orientation could be achieved. It is demonstrated that NAREX can be controlled by various laser parameters, out of which pulse shape plays the most significant role. The effect of elliptic parameter on the rotational excitation and orientation dynamics is also under concern. [ABSTRACT FROM AUTHOR]

The new types of Stoneley waves which can be used in integrated acoustoelectronics have been studied theoretically. It has been established that four types of waves with different polarization and phase velocity can propagate along the interface of the contact between two elastic isotropic media. Numerical calculations for various pairs of contacting metals which can be used as acoustic waveguides in acoustoelectronic integrated circuits have been carried out. [ABSTRACT FROM AUTHOR]

A one-parameter family of time-reversible systems on three-dimensional torus is considered. It is shown that the dynamics is not conservative, namely the attractor and repeller intersect but not coincide. We explain this as the manifestation of the so-called mixed dynamics phenomenon which corresponds to a persistent intersection of the closure of the stable periodic orbits and the closure of the completely unstable periodic orbits. We search for the stable and unstable periodic orbits indirectly, by finding non-conservative saddle periodic orbits and heteroclinic connections between them. In this way, we are able to claim the existence of mixed dynamics for a large range of parameter values. We investigate local and global bifurcations that can be used for the detection of mixed dynamics. [ABSTRACT FROM AUTHOR]

We theoretically explore a scheme for generation of bright circularly and elliptically polarized high-order harmonics by bursts of linearly polarized pulses with a rotating polarization axis. Circularly polarized harmonics are formed if the bursts are comprised of N pulses that uphold an N-fold rotational symmetry, for N > 2. Rotating the polarization axes of the comprising pulses can generate elliptical harmonics with a collectively tunable ellipticity, from circular through elliptic to linear. The method preserves the single-cycle, single-atom and macroscopic physics of 'standard' linearly polarized high harmonic generation, with a high yield and cutoff energy. We investigate the method from a time-domain perspective, as well as a photonic perspective, and formulate the energy and spin-angular momentum conservation laws for this scheme. We find that the case of N = 4 is optimal for this method, resulting with the highest conversion efficiency of elliptical photons. The new features of this source offer new applications to helical ultrafast spectroscopy and ellipsometry. [ABSTRACT FROM AUTHOR]

This paper presents a dual-polarized patch antenna with quasi-elliptic bandpass responses. The proposed antenna is mainly composed of a feeding network, a driven patch, and a stacked patch, with its entire height being $0.09\lambda $ . The feeding network consists of two orthogonal H-shaped lines that coupled to the driven patch, each for one polarization. The elaborately-designed feeding lines not only ensure a sharp roll-off rate at the lower band edge, but also help to achieve low cross polarization and high isolation between two feeding ports. On the other hand, the upper stacked patch provides improved suppression levels at the upper stopband and also an enhanced gain within passband. Consequently, a compact dual-polarized antenna with satisfying filtering performance is obtained, without using extra filtering circuits. For demonstration, an antenna is designed to fit the specification of LTE band (2.49–2.69 GHz). The implemented antenna achieves an average a gain of 9 dBi, a cross-polarization ratio of 29 dB, an isolation of 35 dB within LTE band. The out-of-band suppression level is more than 40 dB within the 2G and 3G frequency bands from 1.71–2.17 GHz. It can be used as the antenna elements in multiband base station antenna arrays to reduce the mutual coupling. [ABSTRACT FROM PUBLISHER]

Polarization gating is a popular and widely used technique in biomedical optics to sense superficial tissues (colinear detection), deeper volumes (crosslinear detection), and also selectively probe subsuperficial volumes (using elliptically polarized light). As opposed to the conventional linearly polarized illumination, we propose a new protocol of polarization gating that combines coelliptical and counter-elliptical measurements to selectively enhance the contrast of the images. This new method of eliminating multiple-scattered components from the images shows that it is possible to retrieve a greater signal and a better contrast for subsurface structures. In vivo experiments were performed on skin abnormalities of volunteers to confirm the results of the subtraction method and access subsurface information. [ABSTRACT FROM AUTHOR]

Optically pumped rubidium atomic magnetometer with elliptically polarized light is demonstrated theoretically and experimentally. Compared with the conventional optical absorption detection mode, the sensitivity of atomic magnetometer for this detection mode can be improved by an order of magnitude under our experimental condition. Some parameters that influence the performance of this magnetometer is studied, which are the form of elliptically polarized light, the amplitude of exciting magnetic field, and the laser intensity. The sensitivity of 2.5 pT/√Hz is obtained when these parameters are optimized. [ABSTRACT FROM AUTHOR]

Using a fully classical model, we have studied sequential double ionization of argon driven by elliptically polarized laser pulses at intensities well in the over-barrier ionization region. The results show that the joint electron momentum distributions in the minor elliptical direction depend strongly on the pulse duration. From pulse numberN = 4 to 10, the clustering regions of the joint electron momentum increase with the pulse duration. For even larger pulse durations, the clustering region does not increase further but the population of the joint electron momentum in these regions changes with the pulse duration. Back analysis of double ionization trajectories shows the phenomenon of multiple ionization bursts and the pulse duration-dependent multiple ionization bursts of the second electron is responsible for the evolution of the joint electron momentum distribution with the pulse duration. [ABSTRACT FROM AUTHOR]

ABSTRACT In this letter, L-T slots-loaded dual-band elliptical polarized antenna etched on a single layer substrate is proposed. This antenna is composed from four T-shaped slots near patch boundary and two pair of L-shaped slots etched at patch corner with a rectangular slot located at the center. These combination slots are found out to produce two different frequency bands for LTE and wireless local area network application. The lower band of 2.5-2.69 GHz and the upper band of 5.725-5.85 GHz are controlled by the T-shaped slots and L-shaped slots, respectively. By symmetrically slots and properly positioning the feed position, the proposed antenna exhibits high gain of 6.91 dBi and 7.22 dBi at 2.6 GHz and 5.8 GHz, respectively, even with the compact dimensions of 44 × 44 × 1.6 mm3. Due to the orthogonal surface currents at first and third resonant modes, the proposed antenna gives an elliptical polarization with axial ratios of 7.536 dB at 2.656 GHz and 5.76 dB at 5.8 GHz. The simulation and measurement results of reflection coefficient, gain, and radiation pattern are comparable. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:184-188, 2016 [ABSTRACT FROM AUTHOR]

We investigated the nonsequential double ionization (NSDI) of by linearly polarized (LP) and elliptically polarized (EP) laser pulses using the classical ensemble model. For the two cases, the ensemble from NSDI was separated into two kinds of subensemble according to the relative momentum along the y-axis , respectively. The results show only for the case of relatively small , the momentum distribution along the x-axis can show a V-like shape obviously, which is according with the experiment [ Phys. Rev. Lett. 99, 263003 (2007)]. What is important is that we firstly examine the role of the repulsion interaction between two electrons for the two kinds of subensemble, and find that the process of NSDI for the case of relatively small exits a strong repulsion interaction which contributes significantly to the V-like shape. However, for the case of relatively big , the repulsion interaction between two electrons is relatively weak, and both the nuclear Coulomb attraction and electric field force dominate the process of NSDI. [ABSTRACT FROM AUTHOR]

This paper is focused on the excitation rates of free electrons of an aluminum (Al) bulk irradiated by an elliptically polarized laser in simulation, using time-dependent density functional theory (TDDFT). The polarized 400 nm, 10 fs laser pulse consisted of two elementary sinusoidal beams, and is adjusted by changing the phase difference φ and the intersection angle θ of the polarization directions between the two beams. The simulation includes cases of φ = π/2 with θ = 30°, θ = 45°, θ = 60°, θ = 90°, θ = 120°, θ = 135°, θ = 150°, and cases of θ = 90° with φ = π/4, φ = π/3, φ = π/2, φ = 2π/3, φ = 3π/4. The absorbed energy, the excitation rates and the density distributions of free electrons after laser termination are investigated. At the given power intensity (1×1014 W cm-2), pulse width (10 fs) and wavelength (400 nm) of each elementary laser beam, computational results indicate that the excitation rate of free electrons is impacted by three major factors: the long axis direction of the laser projected profile, the amplitude difference of the first main oscillation (1st AD), and the total amplitude difference of main oscillations (TAD) of the external electric field. Among the aforementioned three factors for the excitation rate of free electrons, the direction of long axis plays the most significant role. The screen effect is crucial to compare the importance of the remaining two factors. The analysis approach to investigate the electron dynamics under an elliptically polarized laser is both pioneering and effective. [ABSTRACT FROM AUTHOR]

A laser-induced optical gyrotropy is observed in light-sensitive waveguide AgCl-Ag thin films, as a result of spontaneous periodic nanostructure formation, which is the product of interaction of a polarized incident light with the film's substances. Interference of the incident He-Ne laser beam with the excited TE-modes of the waveguide AgCl-Ag thin film and migration of Ag nanoparticles to minima of the interference pattern results in formation of spontaneous periodic nanostructures. Results of our investigation indicate that, in our case, the strength of induced optical rotation depends on the ellipticity of the polarization state of the incident laser beam. It is found that the induced optical activity is caused by two factors in the film: (1) the induced anisotropy; and (2) formed chiral complex planar nanostructures. The portion of each factor in the induced optical gyrotropy depends on the polarization state of the incident laser beam. We have shown that, under incidence of circular polarized light, the chirality is the most efficient factor to produce gyrotropy, but for elliptical polarized incident light, the induced anisotropy, which increases dissymmetry of the film, plays essential role. In this connection, the induced circular dichroism of the samples and optical rotation of the linear polarized probe beam are measured. In this regard, the induced birefringence (∆ n) of the samples is measured. The present study proposes a new candidate for meta-materials and also a simple method for recording the ellipticity and sign of rotation of the polarized incident light. [ABSTRACT FROM AUTHOR]

We explore the influence of the phase of localized plasmon resonances on the magneto-optical activity of nanoferromagnets. We demonstrate that these systems can be described as two orthogonal damped oscillators coupled by the spin-orbit interaction. We prove that only the spin-orbit induced transverse plasmon plays an active role on the magneto-optical properties by controlling the relative amplitude and phase lag between the two oscillators. Our theoretical predictions are fully confirmed by magneto-optical Kerr effect and optical extinction measurements in nanostructures of different size and shape. [ABSTRACT FROM AUTHOR]

We have investigated the polarization property of terahertz (THz) wave emission from gammadion-type photoconductive antennas (PCAs). It was experimentally shown that the polarization of emitted THz wave from the gammadion-type PCAs was elliptic. Finite difference time domain simulation reproduces the experimental observation fairly well. From simulation, we find out that the gammadion-type PCAs have two kinds of radiation; i.e., the radiation from the gap of the PCA and the radiation from the bends of electrode. These two kinds of radiation have different polarization and different time delay, which results in the observed elliptic polarization. [ABSTRACT FROM AUTHOR]

We report results of a high precision phase estimation based on a weak measurement scheme using a commercial light-emitting diode. The method is based on a measurement of the imaginary part of the weak value of a polarization operator. The imaginary part of the weak value appeared due to the measurement interaction itself. The sensitivity of our method is equivalent to resolving light pulses of the order of a attosecond and it is robust against chromatic dispersion. [ABSTRACT FROM AUTHOR]

Abstract: We present a theoretical and experimental study of self-rotation of incident elliptically polarized light on a rubidium atomic vapor. We construct density matrix equations, which are then solved numerically, and further averaged over atomic transit times and a Maxwell–Boltzmann velocity distribution. We calculate the rotation angle as a function of detuning for various laser intensities and polarizations. We compare the calculated results with experimental results and find good agreement between them. [Copyright &y& Elsevier]

Abstract: We present an experimental and theoretical study of the transmission of an arbitrarily polarized laser beam for a Doppler broadened rubidium vapor cell. As the polarization of the probe beam was varied from linear to circular, the transmission for the transitions F g =3→ F e =2,3,4 of the D 2 line of 85Rb atoms was measured and compared with calculated results. In the calculation, the time-dependent absorption coefficient, calculated numerically from the density-matrix equation, was averaged over the velocity distribution and various transit time crossing the laser beam. The final transmission was obtained by considering the Gaussian profile of the laser beam. We found good agreement between experimental and calculated results. [ABSTRACT FROM AUTHOR]

Abstract: A principle possibility of second harmonic generation (SHG) from the surface of a chiral medium by normally incident focused fundamental beam has been shown earlier, and the key features of this phenomenon (forbidden in a planewave approximation) have been outlined in [N.I. Koroteev, V.A. Makarov, S.N. Volkov, Laser Phys. 8 (1998) 532–535]. In our work we have obtained analytical expressions, which describe the distributions of intensity and polarization in the cross-section of a second-harmonic (SH) light beam. It is found that the polarization state drastically changes along the cross-section of the signal light beam. The polarization effects concerning the transversal inhomogeneous polarization distribution were studied in detail. It is shown that the measurement of the polarization state in certain areas of the SH beam cross-section gives us quantitative information directly about the medium material constants. [Copyright &y& Elsevier]

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Elliptically polarized laser pulses (EPLPs) are widely applied in many fields of ultrafast sciences, but the ellipticity (ϵ) has never been in situ measured in the interaction zone of the laser focus. In this Letter, we propose and realize a robust scheme to retrieve the ϵ by temporally overlapping two identical counterrotating EPLPs. The combined linearly electric field is coherently controlled to ionize Xe atoms by varying the phase delay between the two EPLPs. The electron spectra of the above-threshold ionization and the ion yield are sensitively modulated by the phase delay. We demonstrate that these modulations can be used to accurately determine ϵ of the EPLP. We show that the present method is highly reliable and is applicable in a wide range of laser parameters. The accurate retrieval of ϵ offers a better characterization of a laser pulse, promising a more delicate and quantitative control of the subcycle dynamics in many strong field processes. [ABSTRACT FROM AUTHOR]

Recent studies have revealed that there are a large number of low frequency electromagnetic cyclotron waves (ECWs) occurring in and around magnetic clouds (MCs) that are common magnetic structures in interplanetary space. Using magnetic field data from the STEREO spacecraft, this paper investigates polarization properties of ECWs associated with 120 MCs. Results show that the ECWs are highly transverse, strongly polarized waves with large ellipticities. Specifically, almost all of the waves take place with the ratios of transverse power to total power higher than 0.94, polarization degrees greater than 0.85, and ellipticities larger than 0.5. The mean values of these quantities can be up to 0.99, 0.96, 0.85, respectively. In particular, there is a tendency of ellipticities decreasing with respect to the wave normal angles for ECWs with left handed polarization. The decreasing tendency is consistent with the recent theory and simulation results. [ABSTRACT FROM AUTHOR]

Based on the light-induced polarization ellipse rotation effect, we propose an optical Kerr gate (OKG) in which elliptically polarized probe light is used by introducing a pair of crossed quarter-wave plates into the conventional OKG arrangement, placed just before and after the Kerr medium. Transient birefringence induced by the pump beam in the Kerr medium leads to a rotation of the polarization ellipse of the probe beam, hence part of the probe beam would pass through the OKG. Theoretical calculations and experimental results both indicate that the OKG signal intensity would reach the optimum value independent of the pump polarization direction when the probe beam is circularly polarized. This modified OKG measurement is suitable to detect the third-order nonlinearities induced in anisotropic materials. [ABSTRACT FROM AUTHOR]

The analytical expressions for an orthogonal cosine-Gaussian Schell-model (OCGSM) beam propagating in uniaxial crystals orthogonal to the optical axis are derived. Based on the formulas derived, the propagation properties, such as the normalized spectral density, the spectral degree of coherence (SDOC), and the effective beam width of an OCGSM beam in uniaxial crystals are illustrated. Numerical results show that, by changing the beam mode order n and m, the OCGSM beam can split into two- or four-beamlet elliptical beams and keep invariant in uniaxial crystals during propagation, which is different from the conventional Gaussian Schell-model beam. The SDOC of the OCGSM beam will evolve into an elliptical shape and the effective beam width of the OCGSM beam will spread faster along the x direction than the y direction in uniaxial crystals. In addition, the significant influence of the beam mode order, the spatial coherence length and the ratio of the extraordinary refractive index to the ordinary refractive index of the uniaxial crystals on the evolution properties of an OCGSM beam is discussed in detail. [ABSTRACT FROM AUTHOR]

We introduce a chiral metamaterial with strong, non-resonant optical activity and very low polarization ellipticity. We achieve this by combining a meta-atom and its complementary structure into a meta-molecule, resulting in the coupling of magnetic and electric dipole responses. In contrast to either a pair of crosses or complementary crosses, this structure has low dispersion in the optical activity at the transmission resonance. We also study the excitation mechanism in this structure and optimize the optical activity through changing the twist angle. [ABSTRACT FROM AUTHOR]