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The present paper describes a hyper-spectral polarization imaging system based on a non-collinear, acousto-optic tunable filter (AOTF) and a linear polarizer. The paper begins with an analysis of the equivalent relationship of the AOTF to describe the principle of polarization detection of this system. Appropriate parameters of hardware components are assigned later. This system, being electronically controllable and tunable, can not only ensure the precision of imaging but also obtain hyper-spectral polarization signatures. The prototype has two optional working modes, namely, hyper-spectral polarization imaging and hyper-spectral intensity imaging. Moreover, parameters of this system – such as diffraction efficiency, spectral resolution and modulation precision – are tested using a halogen tungsten lamp and an optical fibre spectrometer. The results indicate that this instrument is compact, vibration-insensitive, robust and precisely controllable. The system designed in this paper has further application in polarization detection techniques in military. [ABSTRACT FROM AUTHOR]

A binary three-port reflective grating under second Bragg angle incidence is designed in this paper. Under second Bragg angle incidence, the grating can separate nearly 33% light wave energy into the 2nd order, the 1st order and the 0th diffractive orders, respectively. Rigorous coupled-wave analysis can give numerical calculation to optimize the three-port grating depths and periods. For the optimized reflective three-port grating, TE polarization and TM polarization can have different values of grating depth and period. Compared with the reported three-port binary grating under Bragg angle incidence, the diffraction efficiencies can be improved. Moreover, the modal method is applied to explain the propagating mechanism. The highly efficient three-port binary reflective grating under second Bragg angle incidence would be manufactured in the emerging industry for its novel performance. [ABSTRACT FROM AUTHOR]

We review the geometric evolution of a linearly polarized light wave coupling into an optical fiber and the rotation of the polarization plane in the three dimensional semi-Riemannian manifold. The optical fiber is assumed to be a one-dimensional object imbedded in a 3D semi-Riemannian manifold along the paper. Thus, in the 3D semi-Riemannian manifold, we demonstrate that the evolution of a linearly polarized light wave is associated with the Berry phase or more commonly known as the geometric phase. The ordinary condition for parallel transportation is defined by the Fermi-Walker parallelism law. We define other Fermi-Walker parallel transportation laws and connect them with the famous Rytov parallel transportation law for an electric field , which is considered as the direction of the state of the linearly polarized light wave in the optical fiber in the 3D semi-Riemannian manifold. Later, we define a special class of magnetic curves called by Bishop electromagnetic curves (–curves), which are generated by the electric field along the linearly polarized monochromatic light wave propagating in the optical fiber. In this way, not only we define a special class of linearly polarized point-particles corresponding to –curves of the electromagnetic field along with the optical fiber in the 3D semi-Riemannian manifold, but we also calculate, both numerically and analytically, the electromagnetic force, Poynting vector, energy-exchanges rate, optical angular and linear momentum, and optical magnetic-torque experienced by the linearly polarizable point-particles along with the optical fiber in the 3D semi-Riemannian manifold. [ABSTRACT FROM AUTHOR]

This paper demonstrates the photonic generation of millimetre-wave carriers by frequency octupling of a radio frequency (RF) carrier using a circuit with two parallel arms each containing two polarization modulators in series. The low RF drive power required and the absence of optical filters make this architecture suitable for generating highly stable and tunable optical millimetre-waves. A transfer function representation is used to analyse the operation and a simulation using Virtual Photonic Inc. software package is presented as a proof of concept. The simulation results show very high unwanted optical and electrical side harmonic suppression ratio for a wide range of modulation index compared to the prior art. Further, considering the practical scenario, operating tolerance against the imbalances in the key parameters is established. The unwanted RF sidebands are more than 19 dB and 30 dB below the desired signal power even when a deviation of ±3° is considered in individual RF phase and polarizer angle respectively. [ABSTRACT FROM AUTHOR]

Many optical systems benefit from elements that can absorb a broad range of wavelengths over a wide range of angles, independent of polarization. In this paper, we present a polarization-independent, wide-angle, broadband absorber in the visible regime that exploits strong symmetric and asymmetric resonance modes of electromagnetic dipoles. It makes use of a bilayer cross-pattern structure which is simple, having five layers that include two stacks of metal ribbon in cross-patterns, two dielectric spacers and a metal reflecting layer. Simulations show that the design exhibits a significantly enhanced absorption property when compared to a device with a bilayer metal film structure or any other complex structure of cross-patterns that have no intersection angle. The maximum absorption efficiency of the device is 100% at resonances, and its absorption characteristics can be maintained over a wide range of angles of incidence – up to ± 60° – regardless of the incident polarization. This strategy can, in principle, be applied to other material systems and could be useful in diverse applications, including thermal emitters, photovoltaics and photodetectors. [ABSTRACT FROM AUTHOR]

Field tracing is the generalization of ray tracing and enables electromagnetic system modeling. Harmonic fields are traced through the optical system instead of ray bundles. This allows the smooth combination of different modeling techniques in different subdomains of the system, e.g. to use the rigorous spectrum-of-plane-wave operator for homogeneous media, geometrical optics to trace through a lens and finite element methods to include the effect of some scatterer. All modeling techniques have to be formulated for vectorial harmonic fields. The paper introduces the basic concepts of field tracing and derives the corresponding operator equations. Propagation in homogeneous media is of special concern in field tracing to interconnect the modeling in different subdomains of the system. A new concept for a smart propagation algorithm is presented. Because of the success of geometrical optics in ray tracing, it is reasonable to consider its application in field tracing. In this paper we discuss generalizations of geometrical optics that have been enforced by field tracing. Although the basic field tracing equations are formulated for vectorial harmonic fields, general fields can be treated by suitable decompositions into sets of harmonic modes. [ABSTRACT FROM AUTHOR]

In this paper we explore the physical origin of the transparency induced in absorbing three-level cascade atoms by the simultaneous interplay of two coherent beams of light. By utilizing the scattering technique we offer what we believe is a very convincing physical evidence for the existence, or for the absence, of quantum interference effects in the two considered ladder systems. Bare and dressed states pictures are adopted in two different field regimes when applicable. The conclusions are drawn based on the existence of different excitation pathways and their relative orders of magnitudes. The presented study includes a distinction between the Autler-Townes (AT) and electromagnetically induced transparency (EIT) phenomena. [ABSTRACT FROM AUTHOR]

Crystals of symmetry point groups C3v, C4v, C6v possess an antisymmetric tensor of linear spatial dispersion (LSD) and thus they do not rotate the plane of light polarization. The antisymmetric LSD (ALSD) influences the polarization of the electromagnetic eigenmodes of the crystal and it may be studied through reflection only. In this paper we study the interference by multiple reflection in anisotropic crystal plates of the aforementioned point groups (the optical axis is perpendicular to the plane of incidence). The amplitudes of the reflected and transmitted electromagnetic beams are calculated both in the case of single reflection and in the case of multiple reflection. Differential reflection methods have been proposed and analysed in the case of elliptically and linearly polarized incident beams. The dependences of the multiple reflection intensity and of the differential reflected and transmitted signals on the angle of incidence is calculated for the crystals Ag3AsSe3, ZnO and CdS. It is shown that in the case of total reflection in an anisotropic plate surrounded by an optically denser medium the effects of the ALSD on reflection are enhanced several times. [ABSTRACT FROM AUTHOR]

In 4Pi microscopy, the intensity and polarization distributions of the focal spot directly determine the system resolution, influencing its extended applications. This paper illustrates how the focal spot is affected by the polarization and phase modulation of the incident beams. Various combinations of polarization states and phase modulations are considered and their effects on the focal spot are investigated. The optimal configurations for generating a solid spot and a doughnut-shaped spot are proposed. This paper provides the theoretical basis and reference for extended applications, such as super-resolution confocal microscopy, 4Pi microscopy or 4Pi-STED microscopy. [ABSTRACT FROM AUTHOR]

A novel optical-trap method for improving the trapping capability using a radially polarized narrow-width annular beam (NWAB) has been proposed. In this paper, we theoretically study the tight focusing properties of a radially polarized NWAB, formed by subtly blocking the central portion of a radially polarized Bessel–Gaussian beam (the original doughnut beam), through a high-numerical aperture objective. It is shown that a sub-wavelength focal spot () with a quite long depth of focus (about) can be formed in the vicinity of the focus. Furthermore, the optical trapping forces acting on a metallic Rayleigh particle are calculated for the case where a radially polarized annular beam is applied. Numerical results show that the radially polarized NWAB can largely enhance the transverse trap stiffness and broaden the longitudinal trap range compared with the usage of the original doughnut beam. The influence of the annular factorδon the focusing properties and the trap stiffness is investigated in detail. [ABSTRACT FROM AUTHOR]

In this paper, an analytic theory for the magnetic line source diffraction by a perfect electromagnetic conductor (PEMC) step is developed. Using the duality transformation, introduced by Lindell and Sihvola, transformations have been made from the diffraction of a magnetic line source by a perfect electric conductor (PEC) step. As an application, plane wave diffracted from a planar interface of air and PEMC media is studied. PEC and PMC are the limiting cases, while there is no cross-polarized component. [ABSTRACT FROM AUTHOR]

In this paper we discuss the reconstruction process of one-photon mixed states of partially polarised light. To solve this issue, we obtain the Stokes parameters by means of the degree of polarisation. The density operator describing the examined state is represented with these parameters. In the proposed two-beams method the degree of polarisation is measured on the analysed beam combined with reference beams containing photons with a settled state of polarisation. Coupling these beams allows one to obtain the Stokes parameters from the intensity contrast behind the rotating polariser. We discuss the influence of the quantum uncertainty on this technique of one-photon states reconstruction and we consider it for three aspects – the possibility of reducing the number of reference beams that are needed, the optimal state of polarisation of reference beams and the accuracy of the reconstruction method. [ABSTRACT FROM PUBLISHER]

In this paper, a simple method for obtaining general analytical solutions of the time evolution equations for a fully quantized parametric oscillation process is developed. Heisenberg’s equations for the signal–idler photon annihilation operators are converted into a matrix equation equivalent to a two-state Jaynes–Cummings time evolution equation which has exact analytical solutions. The mean intensity inversion for the coupled signal–idler photon pair is found to undergo fractional revivals for pump photon in a Fock state, provided both signal and idler photons are in occupied Fock states. General collapses and revivals occur for interactions with pump photon in a coherent state, but now with both or either of signal and idler photons in occupied Fock states. An interpretation of the coupled signal–idler photon pair as a circularly polarized two-state system specified by positive and negative helicity states leads to an appropriate description of photon polarization state dynamics governed by the underlying Jaynes–Cummings interaction. [ABSTRACT FROM AUTHOR]

In this paper the authors present the idea for reconstructing one-photon states. Reconstructing a quantum state means measuring the probability distribution P that allows one to write the density operator for the analysed state. The most commonly known approach for the quantum reconstruction is the quantum tomography. Our alternative method assumes that the analysed field is coupled with the reference field which is described by the parameters settled during a measurement. In the proposed gedankenexperiment the degree of linear polarisation (DOLP) of this combined beam is measured using a rotating linear polariser. We state that it is possible to obtain the P-function by changing the parameters of reference beams and by preparing the series of DOLP measurements. This series of data leads to the system of equations. The values of the P-function at chosen points are the unknowns of this system. This article focuses on the numerical algorithm for solving these equations. [ABSTRACT FROM AUTHOR]

This paper describes how single photons of light can be used to determine the index of refraction and material thickness. The results of single-photon transmission and polarization interferometer experiments are analyzed to find the index of refraction and thickness of a microscope coverslip. The single photons were generated using non-collinear spontaneous down-conversion. The experimental results are in good agreement with derived theoretical models. This method of determining optical parameters at the quantum level may be useful in performing non-destructive measurements of light-sensitive samples with high precision. [ABSTRACT FROM PUBLISHER]

A kind of single-polarization and single-mode totally internal reflection photonic crystal fiber (SPSM TIR-PCF) is proposed in this paper. It is a PCF structure with elliptical air holes in the cladding and four large holes in the first ring. A full-vector plane wave expansion method is employed to analyze this PCF structure. The numerical results show that this PCF structure can realize an ultra-broad SPSM bandwidth of 540 nm with a confinement loss less than 0.1 dB km−1, the broadest bandwidth to the best of our knowledge. Moreover, the structure that we proposed can realize a high nonlinear coefficient. [ABSTRACT FROM AUTHOR]

Lithographic masks are an important and increasingly complex part of systems for advanced optical and extreme ultraviolet (EUV) lithography. They introduce polarization and phase effects with a significant impact on the entire system performance. Rigorous electromagnetic field (EMF) modeling of the mask is indispensable for a predictive simulation of lithographic processes. This paper describes several alternative mask models and their integration into a lithography simulation framework. Several examples demonstrate the relevance of an accurate mask diffraction modeling for the prediction of the lithographic process performance. [ABSTRACT FROM AUTHOR]

A linear polarization through a high numerical aperture yields an elliptical spot on the focal plane due to depolarization, which is explained by the vector diffraction theory. Depolarization results from orthogonal polarizations are generated after diffraction by a high numerical aperture lens. In this paper, it has been shown that the elliptical focal shape can be suppressed by adding perpendicular polarization to the incident beam. By a specially designed three-annular-zones-polarizing filter which modifies the linear polarization properly, the ellipticity and volume size of the focal spot are reduced from 0.395 to 0.10 and 0.405λ3 to 0.381λ3, respectively. Furthermore, the filter elongates the focal spot longitudinally by 50.9% and divides the focus into two spots longitudinally separated by 0.754λ. [ABSTRACT FROM AUTHOR]

We propose a theoretical protocol for controlled local implementation of nonlocal operations first, and then give an alternative linear optical protocol to implement the task with a polarization analyzer. In this paper, with local operations, polarization measurement and classical communication, nonlocal operations can be locally implemented with the help of controllers. [ABSTRACT FROM AUTHOR]

In this paper we present a simple and novel method to maximize on-axis coupling efficiency to radially symmetric fibers without the need for extra free space optical elements. The method is based on inserting a segment of step-index multimode fiber (MMF), cleaved to a particular length, between the input fiber and the output fiber (OF). The MMF segment modifies the input field to match the guided modes in the OF. Using this technique we show that, by inserting an appropriate length MMF segment, it is theoretically possible to obtain a coupling coefficient as high as -0.8 dB between a single mode fiber and a graded index ring-shaped fiber and -0.32 dB for a multi-shell fiber. Our experimental measurements showed good agreement with theoretical predictions for the ring fiber. [ABSTRACT FROM AUTHOR]

Certain crystals can split an X-ray's two linear polarization directions by reflecting them equally in two different directions. This paper gives a simple geometrical derivation for the necessary condition identified recently by Baronova and Stepanenko, namely, identical crystal planes under 120○, or three-fold symmetry. An X-ray spectropolarimeter with such polarization-splitting crystals would be particularly useful to diagnose anisotropies in hot, dense plasmas created by intense picosecond lasers. [ABSTRACT FROM AUTHOR]

The results of an experimental study of the third-order nonlinearity and second-order hyperpolarizabilities for several π-conjugated polyenes are given. In this paper we present also a theoretical analysis of the second-order hyperpolarizabilities of polyenes modified. Theoretical calculations of the were carried out at the restricted Hartree–Fock level using the semiempirical Austin model 1 and parametric method 3 (PM3) quantum-chemical self consistent field–molecular-orbital approaches within the HyperChem 7.0 program package. Calculations based on the PM3-type semiempirical molecular-orbital approach have been performed to investigate the energy and structural stabilities of polyenes. We have calculated electronic charge-density distributions of these molecules. Calculations have unambiguously shown an essential influence of modifications of the double bonds and distribution of electronic charge density. Moreover, we have observed a substantial change in the charge-density gradients under the influence of aromatic ring modifications. Changes in the charge-density gradients leads to a strong non-uniformity of the space electronic charge distribution. In the performed calculation we predict that the third-order nonlinearity and second-order hyperpolarizabilities increase with increasing elongation of polyene chain. We found that the theoretical calculations give a true tendency for changes in the corresponding susceptibilities; however, the values are different because of the underestimated absolute energy gap values obtained within the semiempirical methods. [ABSTRACT FROM AUTHOR]

A scheme for experimental creation of a polarization W state is reported in this paper. This scheme is based on a common commercial multiport fibre coupler and single photon source and it is feasible using current technology. This scheme has a higher efficiency and can be easily extended to generate a multiphoton W state with a photon number larger than 4. [ABSTRACT FROM AUTHOR]

In this paper, we describe the design and analyse the performance of a pupil plane mask to achieve super-resolution in high-numerical-aperture coherent focusing systems using linearly polarized incident illumination. We show that a practical resolution enhancement of approximately twice the diffraction-limited resolution is achievable. Our design method generalizes the paraxial theory of Frieden, as it establishes the theoretical limit of super-resolution in a high-numerical-aperture focusing system of a given space-bandwidth product. [ABSTRACT FROM AUTHOR]

The Poincaré equivalence theorem states that any optical element which contains no absorbing components can be replaced by an equivalent optical model which consists of one linear retarder and one rotator only, both of which are uniquely determined. This has many useful applications in the field of optics of polarized light. In particular, it arises naturally in attempts to reconstruct spatially varying refractive tensors or dielectric tensors from measurements of the change of state of polarization of light beams passing through the medium, a field which is known as tensor tomography. A special case is photoelasticity, where the internal stress of a transparent material may be reconstructed from knowledge of the local optical tensors by using the stress-optical laws. We present a rigorous approach to the Poincaré equivalence theorem by explicitly proving a matrix decomposition theorem, from which the Poincaré equivalence theorem follows as a corollary. To make the paper self-contained we supplement a brief account of the Jones matrix formalism, at least as far as linear retarders and rotators are concerned. We point out the connection between the parameters of the Poincaré-equivalent model to previously introduced notions of the characteristic parameters of an optical model in the engineering literature. Finally, we briefly illustrate how characteristic parameters and Poincaré-equivalent models naturally arise in photoelasticity. [ABSTRACT FROM AUTHOR]

The rotation of the polarization direction of linearly polarized light produced by the nonlinear magneto-optic effect has been proposed as a sensitive measure of small magnetic fields. In this paper, the advantages of this technique in optically thick media for precision magnetometry are discussed. Results are presented for measurements of this rotation for resonant light in optically dense Rb vapour under various conditions, with and without buffer gas. The sensitivity of the measurements of small magnetic field is investigated as a function of laser frequency, laser power, beam diameter and atomic density for D[sub 1] line of [sup 87]Rb. [ABSTRACT FROM AUTHOR]

By using the quantum teleportation protocol, Alice can send an unknown quantum state (e.g. the polarization of a single photon) to Bob without ever knowing about it. This paper discusses a quantum teleportation experiment in which nonlinear interactions are used for the Bell state measurement. Since the Bell state measurement is based on nonlinear interactions, all four Bell states can be distinguished. Therefore, teleportation of a polarization state can occur with certainty, in principle. Details of the theory and the experimental set-up are discussed. [ABSTRACT FROM AUTHOR]

The absorption of a weak probe beam for a V-type atom with a closely spaced doublet is studied under conditions such that vacuum-induced interference among decay channels is important. It is shown how the probe polarization as well as the vacuum-induced interference influence the absorption amplitude and spectral structure. Comparing with similar models studied earlier, where probe polarization direction has not been taken into account, the present study shows that probe polarization has significant effects on the absorption spectra. [ABSTRACT FROM AUTHOR]

In our paper we consider the non-classical behaviour of both the Hermitian (observable) Stokes parameters of light and the phase difference of two modes that describe the quantum polarization states of optical field. To characterize the degree of polarization of light we introduce a new quantity taking into account the quantum properties of different quantum states of two orthogonally polarized modes. The problem of determination of the phase difference in two modes of optical field for the quantum polarization states of light is discussed. To describe in general such a quantum field we introduce two pairs of the phase operators: the phase angles for the Stokes parameters of light in a three-dimensional picture of the Poincare sphere. We also consider a special type of the eight-port polarization interferometer (polarimeter) for simultaneous homodyne detection of both the Stokes parameters of light and the polarization phase operators and their fluctuations as well. Using an anisotropic (spatioperiodic) Kerr-like nonlinear medium associated with the polarization interferometer we could generate and also observe the polarization-squeezed phase states of light. The fluctuations in the phase difference between two orthogonally polarized modes for these non-classical states are less than the fluctuations for light in coherent state. [ABSTRACT FROM AUTHOR]

Using the vector diffraction theory, the optical field of the focusing radially polarized Lorentz-Gauss beam with the power-exponent-phase vortex is derived. The normalized intensity distributions of the focusing radially polarized Lorentz-Gauss beam with the power-exponent-phase vortex are numerically demonstrated. The influences of the power order n and the topological charge m on the normalized intensity distribution are examined. The beam centre and the effective beam size, which are defined by the first- and the second-order moments of the intensity distribution, are the important parameters for focus. Therefore, the quantitative effects of the power order n and the topological charge m on the beam centre and the effective beam size are further investigated. This research is beneficial to the optical manipulation which is involved in the radially polarized Lorentz-Gauss beam with the power-exponent-phase vortex. [ABSTRACT FROM AUTHOR]

In this paper, we present a numerical simulation study of the effects of two-photon absorption on soliton trapping occurring between two components decomposed from a soliton pulse. The two pulse components polarize along the polarization directions of the quasi-TE mode and quasi-TM mode in a silicon-on-insulator waveguide. The effects of free carriers generated by two-photon absorption are also investigated, leading to free-carrier absorption and free-carrier dispersion. The simulation image of the propagation of solitons is provided by solving the coupled nonlinear Schrödinger equation satisfied by the quasi-TE mode component and the quasi-TM mode component utilizing the split-step Fourier method with MATLAB. The simulation shows that two-photon absorption and free carriers will hinder the formation of soliton trapping. As the incident pulse power increases, the soliton trapping will occur, inspite of the presence of two-photon absorption and free carriers. The simulation also indicates that if the value of the free-carrier’s lifetime is comparable to the value of the pulse width, the formation of soliton trapping is susceptible to the lifetime of free carriers. With the incident pulse width increasing, soliton trapping forms between the mean peak of two polarization components, whereas it originally formed between the mean peak of TE mode and secondary peak of TM mode at small pulse width. [ABSTRACT FROM AUTHOR]

We present an analytical method to study the angular distribution of THz radiation driven by two-colour laser-induced microplasma in nitrogen gas. Directionally dependent temporal waveforms of the radiated THz pulse is calculated. To do so, we have extended the photo-current model to calculate three-dimensional distribution of the photo-induced current from which the far-field THz radiation is computed. We have also studied the effect of optical polarization state and phase difference on the angular distribution of radiation. Our study shows that for two orthogonally-polarized colours, not only THz polarization state, but also the angular distribution of THz radiation is mostly influenced by the second optical harmonic. The possibility of rotating the angular radiation pattern around the axis of the laser propagation is illustrated for circularly-polarized laser drivers by changing the optical phase difference. [ABSTRACT FROM AUTHOR]

We calculate the differential cross-section of polarized light scattering from a cold and dense atomic ensemble. The regularities in the transformation of the cross-section when increasing the size of the atomic ensemble are analyzed numerically. We show that for typical experimental conditions, an approximate scaling law can be obtained. Very good agreement is found in a comparison with experimental data on the size dependence of a dense and cold cloud of87Rb atoms. [ABSTRACT FROM AUTHOR]

Effective-medium theories for electromagnetic constitutive parameters of particulate composite materials are theories of averages. Standard deviations are absent because of the lack of rigorous theories. But ensemble averages and standard deviations can be calculated from a rigorous theory of reflection by planar multilayers. Average reflectivities at all angles of incidence and two orthogonal polarization states for a multilayer composed of two kinds of electrically thin layers agree well with reflectivities for a single layer with the same overall thickness and a volume-weighted average of the relative permittivities of these two components. But the relative standard deviation can be appreciable depending on the angle of incidence and the polarization state of the incident illumination, and increases with increasing difference between the constitutive parameters of the two layers. This suggests that average constitutive parameters obtained from effective-medium theories do not have uniform validity for all calculations in which they might be used. [ABSTRACT FROM PUBLISHER]

The influence of the width of terahertz (THz) pulses on two-dimensional THz spectroscopy (2DTS) has been studied theoretically via a classical method in which the expressions for the second-order nonlinear polarizations with different nonlinear sources are derived by using a perturbation approach. Compared to the common disposal method in which the THz pulse is treated as a delta function, some terms that were of unknown physical meaning or vanished will come into force when the width is considered. Three types of nonlinear sources, i.e. anharmonicity, nonlinear damping and nonlinear coupling, are considered for a single mode system. The simulation results demonstrate that the width of the incident THz pulse can markedly affect the properties of 2DTS and that different sources have different influences. This study reveals a more practical insight for 2DTS and could provide much information, such as the optimal width and interval of THz pulses, to guide possible future experiments. [ABSTRACT FROM PUBLISHER]

With one weak probe, one strong pumping and one control field, the group velocity dispersion can be balanced by the Kerr effects in a lifetime-broadened four-level atomic medium with two folded levels with proper parameters. This results from the subluminal optical solitons that are formed. Additionally, the conditions for which subluminal solitons occur are given. [ABSTRACT FROM AUTHOR]

We generalize the method of projection to orthogonal basis functions of transverse coordinates for a nonlinear (Kerr medium) fibre and apply this method in the case of a two-mode waveguide (each with two polarization modes). We use orthogonal Bessel functions that fit the choice of the cylindrical geometry of a fibre. The coupled nonlinear Schrödinger equations are derived for the envelopes of electromagnetic field wave trains in each mode. Analytic expressions and numerical results for coupling coefficients are given; the nonlinearity parameters' dependence on fibre radius is illustrated by plots and compared with results of other authors. [ABSTRACT FROM AUTHOR]

It is shown how the standard forms for the spin and orbital components of the angular momentum of a paraxial wave of electromagnetic radiation are obtained from general expressions for the angular momentum that have been derived recently. This result will enable general expressions for angular momentum to be applied with confidence to the many configurations of electromagnetic fields that are more complicated than plane or paraxial waves. [ABSTRACT FROM AUTHOR]

We analyse electromagnetic radiation normally incident to a structurally chiral half-space. We adopt two strategies based respectively on the extract electromagnetic solution to the problem, and a more phenomeno-logical approach based on coupled-wave analysis. We find good agreement between the two methods. [ABSTRACT FROM AUTHOR]

We show that the far-field speckle patterns observed on the transmission of polarization structured light beams through a random diffuser screen have distinct spatial textures, which significantly differ from the texture of the fully developed scalar speckle. In particular, we report on speckle observed using the V-point and C-point polarization singular beams for illumination in this work. The V-point and C-point polarization singularities are generated by a combination of different orbital angular momentum (OAM) states in orthogonal polarizations. When passed through a random diffuser screen, the on-axis far-field diffraction intensity is an incoherent summation of speckle intensities due to the individual OAM states. Unlike the typical grainy structure in the scalar speckle, the speckle patterns observed with V-point and C-point illuminating beams are seen to have a noodle-like and sponge-like textures respectively. The speckle from V-point and C-point illuminations is difficult to distinguish using the usual intensity statistics which does not account for the distinct spatial structure of the speckle patterns. The Gray Level Co-occurrence Matrix (GLCM) methodology was therefore used to extract a number of spatial textural features from the speckle patterns observed using scalar and polarization structured illuminations. The principal component analysis (PCA) technique when applied to the texture parameters shows that it is possible to identify the nature of the illuminating beam by simply observing the texture properties of the resultant speckle pattern. When coherent light beams pass through a random medium resulting in a fully developed speckle pattern, the information regarding the profile of the input beam is generally considered to be lost. Our new observations on distinct textural features in speckle from structured light therefore suggest the possibility of information transmission through random media by means of switching the polarization structure of the incident beam. [ABSTRACT FROM AUTHOR]

The ubiquitous equation for the probability amplitude of entangled polarizations, for quanta propagating in opposite directions, is derived from a straightforward interferometric approach. [ABSTRACT FROM PUBLISHER]

Here, we introduce a compact way of studying coherence properties of a classical field using techniques in Matrix Algebra. We then apply it to the extended sources case to find out the maximum possible polarization obtainable through the propagation of a partially coherent beam. [ABSTRACT FROM AUTHOR]

The Wigner representation of parametric down conversion in the Heisenberg picture is applied to the study of the Rome teleportation experiment. We investigate the physical meaning of the zeropoint inputs at the different areas of the experimental set-up. In particular, we establish a quantitative relationship between the zeropoint sets of modes that are needed for the preparation of the quantum state to be teleported, the idle channels inside the one-photon polarization-momentum Bell-state analyser, and the possibility of performing teleportation of a polarization state with certainty. [ABSTRACT FROM AUTHOR]

We present measurements of the second-order spatial coherence function of thermal light sources using Hanbury-Brown and Twiss interferometry with a digital correlator. We demonstrate that intensity fluctuations between orthogonal polarizations, or at detector separations greater than the spatial coherence length of the source, are uncorrelated but can be used to reduce systematic noise. The work performed here can readily be applied to existing and future Imaging Air-Cherenkov Telescopes used as star light collectors for stellar intensity interferometry to measure spatial properties of astronomical objects. [ABSTRACT FROM AUTHOR]

We investigate the propagation of an Airy beam along the optical axis of a uniaxial medium, and we find that the propagation property of the Airy beam is determined by the ordinary refractive index of uniaxial crystals and is independent of the ratio of the extraordinary to ordinary refractive index. We also know that the polarization state of linearly polarized Airy beams changes gradually during the propagation. This shows that the propagation properties of the Airy beam in uniaxial crystals along the optical axis is distinctly different from that orthogonal to the optical axis. [ABSTRACT FROM PUBLISHER]

Ring-core optical fibre has been successfully demonstrated to have good performance for lifting mode degeneracy, and maintaining orbital angular momentum (OAM) modes in the first radial order, making it promising for applications of OAM mode multiplexing and generation of cylindrical vector beams. The degeneracy lift can be intensified using a hollow ring-core fibre, i.e. when the innermost layer of waveguide is air. The cut-off ring thickness for supporting the lowest OAM modes in radial order are obtained under various refractive index differences between the transport layer and the cladding. To optimize the design, our analysis addresses the dependence of modal properties on the fibre structure parameters, such as the effective area (Aeff) of respective OAM mode, and the differential mode delay. [ABSTRACT FROM AUTHOR]

A simple image rejection mixer based on a dual-polarization quadrature phase shift keying modulator is presented without a 90° hybrid coupler in electrical field. By properly adjusting DC bias points in the integrated modulator and performing balanced photo-detection, the influence of image components can be well rejected. The simulation results show that a 52.24 dB image suppression ratio (ISR) and a conversion efficiency (CE) of −9.17 dB can be achieved by the proposed mixer. Besides, another research on the ISR and CE against non-ideal parameters is carried out. According to the simulation results, it can be figured that the main factor to influence the ISR and CE is the DC drifting which results both of them changed rapidly as the DC bias points deviate from the settled values. On the other hand, with different extinction ratios and LO signal powers and RF signal powers, the mixer still performs good ISR and CE. [ABSTRACT FROM PUBLISHER]

Silicon photonics has begun to use index tunable plasmonic materials, such as graphene and indium tin oxide (ITO), because these materials can have their properties tailored by an external voltage. In this article, a compact plasmonic device, which can work as an optical mode controller and electro-absorption (EA) modulator at 1550 nm, is proposed. The performance of the device is theoretically investigated for ITO. Numerical simulations show that, with a suitable applied voltage to thin ITO layers, the proposed structure can select either only one mode (TE/TM) or both modes initially and then modulate the selected mode: a modulation depth of about 30–50 dB/μm is achieved with a proper choice of the dielectric spacer material. In addition, the proposed structure performance is analysed by replacing the waveguide materials with germanium. The proposed nanoscale device, with high modulation bandwidth (f3 dB = 700–250 GHz) and low-energy consumption (~4.0 fJ/bit), may find applications in the future integrated nanophotonics. [ABSTRACT FROM AUTHOR]

We present a novel concept for the generation of ultrashort polarization-shaped bichromatic laser fields. The scheme utilizes a 4f polarization pulse shaper based on a liquid crystal spatial light modulator for independent amplitude and phase modulation of femtosecond laser pulses. By choice of either a conventional (p) or a composite (p-s) polarizer in the Fourier plane, the shaper setup enables the generation of parallel linearly and orthogonal linearly polarized bichromatic fields. Additional use of a γ/4 wave plate behind the setup yields co-rotating and counter-rotating circularly polarized bichromatic fields. The scheme allows to independently control the spectral amplitude, phase and polarization profile of the output fields, offering an enormous versatility of bichromatic waveforms. [ABSTRACT FROM AUTHOR]

Using the hybrid anti-symmetrized coupled channels method [Majety V.P.; et al. New J. Phys. 2015, 17, 063002], we calculate photoemission spectra from Helium in an elliptically polarized near infrared pulse. We conclude that electron correlation has no impact on the direction of peak emission and therefore cannot explain discrepancies found between calculated and measured offset angles in an attoclock setting. The fully quantum calculations were made possible by exploiting angular preponderance rules in near-circular polarized light. [ABSTRACT FROM AUTHOR]