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Showing papers on "Polarization rotator published in 1991"


Journal ArticleDOI
TL;DR: It is shown analytically that the evolution equation can be reduced to the nonlinear Schrödinger equation if the variation length is much shorter than the soliton period.
Abstract: The effects of randomly varying birefringence on solitons are studied. It is shown analytically that the evolution equation can be reduced to the nonlinear Schrodinger equation if the variation length is much shorter than the soliton period. The soliton does not split at high values of the average birefringence, but it does undergo spreading and loss of polarization. A soliton with a temporally constant initial state of polarization is still largely polarized after 40z0 if the normalized birefringence is δ ≤ 1.3.

243 citations


Journal ArticleDOI
TL;DR: In this article, the basic properties of electric polarization response in crystalline dielectrics are theoretically analyzed and the effect of sample termination on the polarization response is considered in detail, and the problem of the adequate theoretical definition of these phenomena is addressed.
Abstract: The basic properties of electric polarization response in crystalline dielectrics are theoretically analysed. Spontaneous polarization, pyroelectricity, piezoelectricity, flexoelectricity (polarization response to strain gradient) and thermopolarization effect (polarization response to temperature gradient) are discussed on the basis of a unified approach. Special attention is paid to the problem of the adequate theoretical definition of these phenomena. The effect of the sample termination on the polarization response is considered in detail.

210 citations


Journal ArticleDOI
TL;DR: In this article, a model for PMD with random mode coupling was developed, and an explicit equation for the time-of-flight distribution was presented, and the coupling length on the order of 20-30 m was estimated.
Abstract: Polarization mode dispersion (PMD) in short and long single-mode fibers was measured by a polarization-maintaining Michelson interferometer. A nonnegligible PMD was found in some standard fibers. The sensitivity enables PMD to measure the bend-induced PMD of a fiber rolled on a 28-cm diameter drum. A theoretical model for PMD with random mode coupling is developed, and an explicit equation for the time-of-flight distribution is presented. Comparison between measurements on short and long fibers with residual birefringence leads to an estimation of the coupling length on the order of 20-30 m. >

187 citations


Journal ArticleDOI
TL;DR: In this paper, a mathematical description of the polarization conversion process was developed, using a method that transforms the grating surface into a planar system, and the predicted polarization conversion was compared very favorably with data for surfacemode-enhanced conversion.
Abstract: If a surface-modulated diffraction grating is arranged so that the scattering vector does not lie in the plane of incidence of the illuminating radiation, then polarization conversion can occur. This conversion can be strongly enhanced if a surface mode, such as a surface-plasmon-polariton or guided mode, is excited at the grating surface. In this paper we develop a mathematical description of the polarization conversion process, using a method that transforms the grating surface into a planar system. The predicted polarization conversion is compared very favorably with data for surface-mode-enhanced conversion.

120 citations


Journal ArticleDOI
TL;DR: In this article, a polarization insensitive, electrically tunable Fabry-Perot structure is demonstrated, which is realized by using a twisted structure of a nematic liquid crystal such that the molecules at one surface are orthogonal to those at the other surface.
Abstract: A polarization insensitive, electrically tunable Fabry–Perot structure is demonstrated. The polarization insensitivity is realized by using a twisted structure of a nematic liquid crystal such that the molecules at one surface are orthogonal to those at the other surface. In the high‐field regime, this configuration can be thought of as a structure composed of two orthogonal, birefringent slabs with the electrically controllable thickness. At low voltages the device is polarization sensitive but becomes polarization insensitive at relatively higher voltages. In the polarization insensitive region, the linewidth of the transmission peak is of the order of 0.5 nm and the tuning range is about 15 nm.

100 citations


Patent
Brian L. Heffner1
06 Sep 1991
TL;DR: In this article, the distortion of the light beam polarization caused by a single-mode optical fiber is corrected by introducing two different linearly polarized light beams and measuring Stokes parameters which are used to construct a calibration matrix that is inverted and multiplied times measured Stokes parameter of subsequent measurements to yield true stokes parameters.
Abstract: An instrument includes a polarized optical source for producing three sequential predetermined states of polarization of a light beam and an optical polarization meter for measuring the polarization of a portion of the light beam transmitted by or reflected from an optical network by splitting it into four beams, passing three of the beams through optical elements, measuring the transmitted intensity of all four beams, and calculating Stokes parameters. The light beam enters the optical polarization meter through a single-mode optical fiber that acts as a spatial filter for controlling the position and alignment of the beam with respect to the optical elements. The distortion of the light beam polarization caused by this optical fiber is corrected by introducing two different linearly polarized light beams and measuring Stokes parameters which are used to construct a calibration matrix that is inverted and multiplied times measured Stokes parameters of subsequent measurements to yield true Stokes parameters. The three sequential predetermined states of polarization yield three corresponding Jones input vectors, and the Stokes parameters for the responses of the optical network are converted to three Jones output vectors. A Jones matrix for the optical network to within a complex constant is then computed from the Jones input and output vectors. Relative polarization sensitivity can be determined from this matrix for the optical network. The relative distortion caused by the optical network can be corrected by multiplying by the inverse of the matrix during later measurements through the optical network. Additionally, power measurements on the optical network and a substituted optical through enable absolute determinations and corrections.

81 citations


Journal ArticleDOI
TL;DR: In this article, the Stokes parameters were measured in the 5-80-eV energy region for synchrotron-radiation beams on the VUV to soft X-ray beamlines at the Photon Factory.
Abstract: The Stokes parameters, which completely represent the polarization state of light, have been measured in the 5–80-eV energy region for synchrotron-radiation beams on the VUV to soft X-ray beamlines at the Photon Factory. Various states of polarization were produced for the emerging beam by deflecting the incoming beam vertically with respect to the entrance slit of the monochromator with a premirror of the beamline. The resultant beam was polarization-analyzed using a polarimeter comprising two triple-reflection polarizers. Increasing the beam-deflection angle was found to result in a change in the polarization state from predominantly horizontal linear polarization to elliptical polarization. This procedure could be used both to produce and to verify circular polarization with | P c | ≳ 80% in the energy range 60–80 eV, which could be immediately applied to MCD experiments. Unpolarized light could clearly be distinguished from circularly polarized light. The unpolarized component was found to become larger with increasing energy on a soft X-ray beamline; this was shown to be mainly due to scattering by beamline optical elements.

61 citations


Patent
Jean-Marc Delavaux1
25 Feb 1991
TL;DR: In this paper, a phase independent coherent lightwave detection scheme was proposed, where phase independence was incorporated by replacing the pair of output polarization maintaining optical couplers with a pair of phase diversity optical hybrids.
Abstract: A polarization independent coherent lightwave detection arrangement is disclosed which utilizes an optical hybrid (11) including a single polarization beam splitter (12) and a set of three polarization maintaining optical couplers (one input (22), two output (16,20)). By controlling the polarization state of the local oscillator to remain at a fixed value, polarization independent recovery of a transmitted data signal may be accomplished. Phase independence may be incorporated by replacing the pair of output polarization maintaining optical couplers with a pair of phase diversity optical hybrids.

61 citations


Journal ArticleDOI
TL;DR: In this paper, a compact polarization-insensitive liquid crystal filter is demonstrated using the polarization diversity technique, where the incoming signal is split into two orthogonally polarized beams with a calcite crystal and the beams are filtered using two regions of the liquid crystal Fabry-Perot filter.
Abstract: A compact polarization-insensitive liquid crystal filter is demonstrated using the polarization diversity technique. The incoming signal is split into two orthogonally polarized beams with a calcite crystal and the beams are filtered using two regions of the liquid crystal Fabry-Perot filter. The optic axes in these two regions are made orthogonal by controlling the surface structure. It is shown that a wide tuning range of 70 nm is possible with a band-pass of about 0.6 nm. Using arbitrarily polarized input light it is demonstrated that polarization-dependent power fluctuations are less than 1 dB. >

46 citations


Journal ArticleDOI
TL;DR: The results of beam polarization measurements performed in 1990 at the CERN Large Electron Positron storage ring (LEP) are reported in this article, where a significant asymmetry was observed in the Compton back-scattered photon distribution when illuminating the LEP electron beam with circularly polarized laser light.

46 citations


Journal ArticleDOI
TL;DR: The bandwidth in which the first-order approximation of the principal states of polarization of a single-mode fiber can be assumed valid is examined and theoretical values of the bandwidth are provided that have been experimentally verified on a 2-km-long concatenation of single- mode dispersion-shifted fibers.
Abstract: The bandwidth in which the first-order approximation of the principal states of polarization of a single-mode fiber can be assumed valid is examined. The principal states of polarization and their bandwidth are found for a fiber with both constant coupling and birefringence, and the relationship with the fiber’s eigenmodes is examined. On the basis of these results, a fiber cascade is analyzed, and a Monte Carlo simulation provides theoretical values of the bandwidth that have been experimentally verified on a 2-km-long concatenation of single-mode dispersion-shifted fibers.

Journal ArticleDOI
14 Oct 1991-EPL
TL;DR: In this article, the spin-orbit induced hybridization of basis functions of different spatial symmetry types was shown to predict large polarization features depending sensitively on the top layer spacing of a cubic cubic crystal.
Abstract: Photoelectrons emitted normal to (001) surfaces of nonmagnetic centrosymmetric cubic crystals by off-normally incident linearly and unpolarized light are spin polarized. From symmetry, the polarization is perpendicular to the incidence plane and its size has no azimuthal dependence. As is seen analytically, the effect is due to the spin-orbit-induced hybridization of basis functions of different spatial symmetry types. Relativistic one-step-model multiple scattering calculations for Pt(001) and Pd(001) predict large polarization features depending sensitively on the top layer spacing.

Journal ArticleDOI
TL;DR: Good agreement is found between the model calculations and the experimental results indicating that edge birefringence can be attributed to the change in polarization of light that is refracted and reflected by dielectric interfaces.

Patent
28 Jan 1991
TL;DR: In this article, the authors proposed a method for determining the direction of the polarization vector of a light beam by using a compact polarization beam splitter that receives a beam of light, separates the beam into two perpendicular polarization components and directs these components to a pair of optical detectors and associated circuits.
Abstract: Apparatus and method for determining dynamically the polarization vector direction, or polarization vector components and associated temporal phase angle, of a light beam. The apparatus includes a compact polarization beam splitter that receives a beam of light, separates the beam into two perpendicular polarization components and directs these components to a pair of optical detectors and associated circuits that form the sum and difference signals of the electrical signals produced by the optical detectors. This produces a projection of the polarization vector on a given direction. If the light is generally elliptically polarized, use of two such polarization beam splitters and four optical detectors allows reconstruction of the polarization ellipse for the light beam. Alternatively, use of one such polarization beam splitter, two optical detectors and a rotating wave plate in a multiplexed configuration allows reconstruction of the polarization ellipse. The polarization detector is very compact and may be housed in a container that is no more than a few cm. in diameter.

Patent
14 Jan 1991
TL;DR: In this article, the authors proposed a method to provide the polarization independent waveguide type optical device which eliminates the polarization dependency on incident signal light, where one piece or >= 2 pieces of polarization rotating devices are installed in the mid-way of the waveguide in such a way that the optical path length to the input of the horizontally polarized wave and the path length of the input light of the vertically polarized wave are equal to each other.
Abstract: PURPOSE:To provide the polarization independent waveguide type optical device which eliminates the polarization dependency on incident signal light. CONSTITUTION:One piece or >=2 pieces of polarization rotating devices 11 for converting a horizontally polarized wave (TE) to a vertically polarized wave (TM) or the vertically polarized wave to the horizontally polarized wave are installed in the mid-way of the waveguide in such a manner that the optical path length to the input of the horizontally polarized wave and the optical path length of the input light of the vertically polarized wave are equal to each other.

Journal ArticleDOI
TL;DR: In this paper, the authors discuss ± π phase jumps associated with the geometric part of the phase change in the evolution of a spin -1/2 particle and describe some useful results in polarization optics including some obtained by this method.
Abstract: The possibility of making arbitrary SU(2) transformations on the polarization state of a light beam with a fixed k vector using combinations of quarterwave and halfwave plates allow the simulation on the light polarization system of an arbitrary stationary magnetic field or of interesting time-varying magnetic fields acting on spin 1/2 particles. This enables the study of several intriguing properties of spin -1/2 or SU(2) phases by optical interferometry. Such studies lead to interesting insights into the quantum evolution of spin systems. We discuss ± π phase jumps associated with the geometric part of the phase change in the evolution of a spin -1/2 particle. Using results obtained from polarization transformations, we show that when a rotating magnetic field acts on a spin, for certain critical rotation frequencies, all spin states become cyclic. Geometric phase experiments involving mixed evolution of light beams in direction and polarization led recently to a method for decomposing such an evolution that makes the analysis of such problems conceptually simpler; particularly where polarization changes are accompanied with mirror reflections for it separates the two physically distinct functions of a mirror, namely a change of direction of the beam and a polarization transformation. We show the consistency of this method with other existing methods and describe some useful results in polarization optics including some obtained by this method. For example, we show that the effect of an odd number of ideal metal-mirror reflections can be ‘cancelled’ by introducing just one halfwave plate in the light path.

Patent
10 Jul 1991
TL;DR: In this article, the polarization beam splitter array is constituted of plural, for instance, eight pieces of polarization beam splitters 2-9, placed adjacently in the direction being parallel to the reflecting direction of an (s) polarized light 27.
Abstract: PURPOSE:To obtain a polarizer which has a large luminous flux diameter and is used for a very intense light. CONSTITUTION:The polarization beam splitter array is constituted of plural, for instance, eight pieces of polarization beam splitters 2-9. The polarization beam splitter 2-9 are placed adjacently in the direction being parallel to the reflecting direction of an (s) polarized light 27. The polarization separating surfaces 10-17 of the adjacent polarization beam splitters 2-9 are placed so as to be orthogonal to each other. A (p) polarization component of incident light 20, 25 transmits through the polarization beam splitter array 1, and an (s) polarization component is reflected.

Journal ArticleDOI
TL;DR: In this paper, photorefractive polarization couplers written internally in germanium-doped elliptical core fibers at 488, 514, and 532 nm were shown to achieve complete power transfer between the orthogonal polarization modes of the fiber.
Abstract: Photorefractive polarization couplers written internally in germanium-doped elliptical core fibers at 488, 514, and 532 nm are reported. Complete power transfer between the orthogonal polarization modes of the fiber was achieved for couplers written at 514 and 488 nm, respectively. It is shown that the couplers are nonuniform in length because of the high photoinduced attenuation and also due to two-photon absorption. Polarization coupling of higher order modes is also demonstrated at shorter wavelengths where their polarization beat lengths match the polarization beat length of the fundamental mode at which the coupler was written. >

Journal ArticleDOI
TL;DR: In this article, the effect of interference between the LP01 and LP02 polarization modes propagating along a linearly birefringent bimodal optical fiber is considered.
Abstract: Modal interference between the LP01 and LP02 polarization modes propagating along a linearly birefringent bimodal optical fibre is considered. On the basis of Jones matrix formalism, radial Stokes parameters containing information about the resultant polarization and mode pattern are derived in the monochromatic and the quasimonochromatic cases. Particular cases with different polarization inputs are considered. The application of the obtained results to fibre-optic sensors and wavelength filter structures is discussed.

Journal ArticleDOI
TL;DR: In this article, high frequency modulation of a LNA laser beam polarization has been used to pump 4He (23S1) metastable atoms, and new resonances, never observed before, have been studied theoretically and experimentally, and application to high sensitivity magnetometers is suggested.

Journal ArticleDOI
TL;DR: In this article, the state of polarization of a quasi-monochromatic beam diffracted by a perfect crystal in the Bragg geometry is described in the framework of standard concepts of optics: the polarization transfer function, the coherence matrix, the Stokes decomposition, and the Mueller matrix.
Abstract: In this paper, the state of polarization of a quasi-monochromatic beam diffracted by a perfect crystal in the Bragg geometry is described in the framework of standard concepts of optics: the polarization transfer function (PTF), the coherence matrix, the Stokes decomposition, and the Mueller matrix. From simulations based on the dynamical theory of X-ray diffraction, we analyze how the phase and amplitude of the σ and π polarization components vary during several successive reflections on perfect single crystals. Different crystal arrangements are then compared from the point of view of their polarization transfer properties, i.e. the conventional double crystal (+,−) monochromator, the antiparallel (dispersive) four-crystal setting and another four-crystal configuration with two “twisted” two-crystal modules. The latter is discussed carefully as it makes it possible, in principle, to recover high circular polarization rates (even at Bragg angles approaching 45°) but at the expense of increasing losses in the transmitted intensity. Of particular interest is the comparison of the polarization transfer properties of different crystal pairs, e.g. Si(111) or Ge(111) single crystals. Finally, we call attention to the potential advantages of using asymmetric reflections.

Journal ArticleDOI
TL;DR: In this paper, the propagation of short pulses in linearly birefringent optical fibres is considered analytically with the help of a variational (Lagrangian) approach for two coupled nonlinear Schr?dinger equations.
Abstract: Propagation of short pulses in linearly birefringent optical fibres is considered analytically with the help of a variational (Lagrangian) approach for two coupled nonlinear Schr?dinger equations. For nearly equal amplitudes of the polarization pulses we study the trapping of solitons due to the nonlinear coupling in the case of strong birefringence, and we find also the amplitude threshold for the trapping when the solitons are produced by a symmetric output pulse. In the case of small birefringence we propose an analytical explanation of the soliton instabilities observed earlier in numerical simulations. The analysis demonstrates instability of the fast polarization mode and stability of the slow one, the effect having a threshold which depends on birefringence. Our results may also be applied to an elliptically birefringent fibre when the birefringence is large.

Journal ArticleDOI
TL;DR: In this article, a surface emitting laser structure for controlling its output polarization is proposed, where high refractive index films are placed on the side walls of a dielectric multilayer reflector.
Abstract: In this paper, we propose a surface emitting laser structure for controlling its output polarization. By preparing high refractive index films on the side walls of a dielectric multilayer reflector, we can provide a differential loss to the orthogonal polarizations. We estimate the reflectivity dependence on the polarization direction of this reflector and conclude that the control of polarization direction is possible by employing this structure.

Patent
12 Oct 1991
TL;DR: In this article, a dual septum polarization rotator with a pair of stepped septums disposed in spaced, orthogonal relation to each other within opposite end portions of the square waveguide is described.
Abstract: A dual septum polarization rotator which, in the presently preferred embodiment thereof, includes a square waveguide and a pair of stepped septums disposed in spaced, orthogonal relation to each other within opposite end portions of the square waveguide A first one of the septums extends horizontally between the side walls of the waveguide, parallel to the top and bottom walls of the waveguide, and the other/second one of the septums extends vertically between the top and bottom walls of the waveguide, parallel to the side walls of the waveguide The first septum, in cooperation with the waveguide, defines first and second input ports, and, the second spectum, in cooperation with the waveguide, defines first and second output ports The spacing between the first and second septums defines a central, open, nonseptum region within the waveguide In operation, the first septum functions to convert the polarization of a first excitation signal introduced into the first input port from a first polarization to a second polarization, and the second septum functions to convert the second polarization into a third polarization orthogonal to the first polarization, for output, via the first output port, as a first output signal For example, if the first polarization is horizontal polarization, then the second polarization is circular polarization, and the third polarization is vertical polarization The polarization rotator of the present invention is also capable of dual mode operation, whereby the polarization of a second excitation signal introduced into the second input port is simultaneously rotated for output, via the second output port, as a second output signal

Patent
10 Jun 1991
TL;DR: In this article, an improved optical pumping magnetometer with sequential polarization for measurement of weak magnetic fields was proposed, which sequentially modifies the polarization either in the direction of the polarization or from clockwise to counterclockwise circular polarization.
Abstract: An improved optical pumping magnetometer with sequential polarization for measurement of weak magnetic fields involves a device which sequentially modifies the polarization either in the direction of the polarization or from clockwise to counterclockwise circular polarization. As a result of the sequential modification of the polarization, the magnetometer for measurement of the weak magnetic fields has excellent isotropy while still retaining a simple construction and a small overall dimension to the device by using only a single cell.

Journal ArticleDOI
TL;DR: A novel fiber-optic gyroscope with a single-mode diode laser as the light source and two polarization scramblers as time-varying depolarizers is demonstrated, which reduces the nonreciprocal phase noise induced by the cross coupling between polarization modes in single- mode fibers.
Abstract: A novel fiber-optic gyroscope with a single-mode diode laser as the light source and two polarization scramblers as time-varying depolarizers is demonstrated. This arrangement reduces the nonreciprocal phase noise induced by the cross coupling between polarization modes in single-mode fibers. The experimental results show that a phase-noise reduction factor of 18 can be achieved.

Journal ArticleDOI
T. Chu1
TL;DR: In this paper, the diffraction-induced cross polarizations calculated from the differential phase shift between the fundamental TEM/sub 00/ and higher order TEM /sub 01/ Gaussian beam modes, which represent principal and cross-polarization components, respectively, are in agreement with measured data.
Abstract: For an offset dual-reflector antenna design of zero geometrical optics cross polarization, the diffraction-induced cross polarizations calculated from the differential phase shift between the fundamental TEM/sub 00/ and higher order TEM/sub 01/ Gaussian beam modes, which represent principal and cross-polarization components, respectively, are in agreement with measured data. Since this residual cross polarization in the main reflector aperture is in approximate phase quadrature with the principal polarization, the far-field cross polarization is in phase with the principal polarization. Thus, both principal polarizations exhibit the same slight rotation for a given far-field direction. An important consequence is the preservation of orthogonality between two orthogonal linear polarizations from the feed. >

Patent
05 Feb 1991
TL;DR: In this paper, an electro-optic crystal is used as an electronically-controllable half-wave retardation plate to rotate the polarization of the laser light periodically as the light passes through the converter as it circulates in the cavity.
Abstract: Polarization self-modulation of a laser produces high-frequency optical modulation without the use of high-speed electronics. This is accomplished by inserting into a laser cavity a polarization converter, which rotates the polarization of the laser light periodically as the light passes through the converter as it circulates in the cavity. The frequency of the modulation is determined by the cavity length. In one configuration, a quarter-wave retardation plate is used as the intracavity polarization converter in a Fabry-Perot laser. In a second embodiment, the converter is an electro-optic crystal which acts as an electronically-controllable half-wave retardation plate.

Patent
Brian L. Heffner1
22 Jan 1991
TL;DR: An optical polarization meter as discussed by the authors measures the polarization of a light beam by splitting it into four beams, passing three of the beams through optical elements, measuring the transmitted intensity of all four beams by means of electronic sensors, and calculating the Stokes parameters from the results.
Abstract: An optical polarization meter measures completely the polarization of a light beam by splitting it into four beams, passing three of the beams through optical elements, measuring the transmitted intensity of all four beams by means of electronic sensors, and calculating the Stokes parameters from the results. One of the optical elements is a horizontal linear polarizer, the second is a linear polarizer with a polarization direction oriented at a 45 degree angle about the optic axis relative to the first, and the third element is a circular polarizer. The measurement of the fourth beam provides a normalizing factor proportional to the incident total intensity that enables one to determine all four Stokes parameters, i.e. the complete state of polarization. This determination is done electronically. The input beam enters the device through a single-mode optical fiber that acts as a spatial filter which, together with other optical elements, controls the position and alignment of the beams through the device.

Patent
Naganuma Norihisa1
27 Nov 1991
TL;DR: In this paper, the authors proposed a polarization independent optical device which is capable of eliminating the apparent polarization dependence of a dielectric multi-layer film and permitting the design of an optical path at an optional angle of incidence of light beam.
Abstract: A polarization independent optical device capable of eliminating the apparent polarization dependence of a dielectric multi-layer film and permitting the design of an optical path at an optional angle of incidence of light beam. The polarization independent optical device comprises a tapered double-refractive crystal disposed so that an optic axis thereof is perpendicular to an incident optical path, and a dielectric multi-layer film disposed on an exit side of light beam with respect to the tapered double-refractive crystal.