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Showing papers on "Optical polarization published in 2006"


Journal ArticleDOI
TL;DR: The transfer code SEDONA as mentioned in this paper has been developed to calculate the light curves, spectra, and polarization of aspherical supernova models from the onset of free expansion in the supernova ejecta.
Abstract: We discuss Monte Carlo techniques for addressing the three-dimensional time-dependent radiative transfer problem in rapidly expanding supernova atmospheres. The transfer code SEDONA has been developed to calculate the light curves, spectra, and polarization of aspherical supernova models. From the onset of free expansion in the supernova ejecta, SEDONA solves the radiative transfer problem self-consistently, including a detailed treatment of gamma-ray transfer from radioactive decay and with a radiative equilibrium solution of the temperature structure. Line fluorescence processes can also be treated directly. No free parameters need be adjusted in the radiative transfer calculation, providing a direct link between multidimensional hydrodynamic explosion models and observations. We describe the computational techniques applied in SEDONA and verify the code by comparison to existing calculations. We find that convergence of the Monte Carlo method is rapid and stable even for complicated multidimensional configurations. We also investigate the accuracy of a few commonly applied approximations in supernova transfer, namely, the stationarity approximation and the two-level atom expansion opacity formalism.

335 citations


Journal ArticleDOI
TL;DR: Experimental results are presented that illustrate that the technique is accurate near object limbs, as the theory predicts, with less precise, but still useful, results elsewhere.
Abstract: When unpolarized light is reflected from a smooth dielectric surface, it becomes partially polarized. This is due to the orientation of dipoles induced in the reflecting medium and applies to both specular and diffuse reflection. This paper is concerned with exploiting polarization by surface reflection, using images of smooth dielectric objects, to recover surface normals and, hence, height. This paper presents the underlying physics of polarization by reflection, starting with the Fresnel equations. These equations are used to interpret images taken with a linear polarizer and digital camera, revealing the shape of the objects. Experimental results are presented that illustrate that the technique is accurate near object limbs, as the theory predicts, with less precise, but still useful, results elsewhere. A detailed analysis of the accuracy of the technique for a variety of materials is presented. A method for estimating refractive indices using a laser and linear polarizer is also given.

242 citations


Journal ArticleDOI
Qiwen Zhan1
TL;DR: A simple setup for generating evanescent Bessel beams is proposed, where the entire beam is p-polarized with respect to the dielectric-metal interface, enabling excitation of surface plasmons from all directions.
Abstract: A simple setup for generating evanescent Bessel beams is proposed. When a radially polarized beam is strongly focused onto a dielectric-metal interface, the entire beam is p-polarized with respect to the dielectric-metal interface, enabling excitation of surface plasmons from all directions. The angular selectivity of surface plasmon excitation mimics the function of an axicon, leading to an evanescent nondiffracting Bessel beam. The created evanescent Bessel beam may be used as a virtual probe for near-field optical imaging and sensing applications.

202 citations


Book
01 Jan 2006
TL;DR: In this article, a Monte Carlo model is used to model the effect of light polarization in random multiple scattering media, and the degree of light polarization in laser speckles from Turbid Media.
Abstract: Tissue Structure and Optical Models.- Polarized Light Interactions with Weakly Scattering Media.- Polarized Light Interactions with Strongly Scattering Media.- Polarization Properties of Tissues and Phantoms.- Polarization-Dependent Interference of Multiply Scattered Light.- Decay of Light Polarization in Random Multiple Scattering Media.- Degree of Polarization in Laser Speckles from Turbid Media.- Monte Carlo Modeling of Polarization Propagation.- Polarization-Sensitive Optical Coherence Tomography.- Biomedical Diagnostics and Imaging.

193 citations


Journal ArticleDOI
TL;DR: Experimental implementation of six logic functions (including XOR, XNOR, AND, NOR, etc.) operating at 10 Gb/s were realized by simply adjusting two polarization controllers in the setup.
Abstract: We have demonstrated simple reconfigurable all-optical logic operations based on four-wave mixing in semiconductor optical amplifier and encoding information in the polarization of the input signals. Experimental implementation of six logic functions (including XOR, XNOR, AND, NOR, etc.) operating at 10 Gb/s were realized by simply adjusting two polarization controllers in the setup

184 citations


Journal ArticleDOI
Qiwen Zhan1
TL;DR: The cylindrical decomposition of a circularly polarized vortex beam is decomposed into radial and azimuthal polarization and sheds light on the connections between orbital angular momentum and the spin of the light beams.
Abstract: The properties of circularly polarized vortex beams in cylindrical polarization bases are studied. A circularly polarized vortex beam is decomposed into radial and azimuthal polarization. With the proper combination of vortex charge and the handedness of the circular polarization, a focal field with an extremely strong longitudinal component as well as a flat-topped profile can be obtained. The cylindrical decomposition also sheds light on the connections between orbital angular momentum and the spin of the light beams.

180 citations


Journal ArticleDOI
TL;DR: The generation of a radially polarized laser beam from an extremely simple laser resonator including a c-cut Nd:YVO4 crystal as a laser medium by simply adjusting the distance between two cavity mirrors.
Abstract: We demonstrated the generation of a radially polarized laser beam from an extremely simple laser resonator including a c-cut Nd:YVO4 crystal as a laser medium. The oscillation in the radial polarization was based on the optical path difference between an extraordinary ray and an ordinary ray induced by the birefringence of the crystal. By simply adjusting the distance between two cavity mirrors, only the extraordinary ray became stable for the oscillation, resulting in the generation of a radially polarized beam. The beam was very stable even at low power output and is expected to be a promising radially polarized laser source because of its excellent simplicity.

179 citations


Proceedings ArticleDOI
TL;DR: In this paper, a four-element fiber array has demonstrated 470 watts of coherently phased, linearly polarized light energy in a single far-field spot, each element consists of a single-mode fiber-amplifier chain.
Abstract: A four-element fiber array has demonstrated 470 watts of coherently phased, linearly polarized light energy in a single far-field spot. Each element consists of a single-mode fiber-amplifier chain. Phase control of each element is achieved with a Lithium-Niobate phase modulator. A master laser provides a linearly polarized, narrow linewidth signal that is split into five channels. Four channels are individually amplified using polarization maintaining fiber power amplifiers. The fifth channel is used as a reference arm. It is frequency shifted and then combined interferometrically with a portion of each channel's signal. Detectors sense the heterodyne modulation signal, and an electronics circuit measures the relative phase for each channel. Compensating adjustments are then made to each channel's phase modulator. This effort represents the results of a multi-year effort to achieve high power from a single element fiber amplifier and to understand the important issues involved in coherently combining many individual elements to obtain sufficient optical power for directed energy weapons. Northrop Grumman Corporation and the High Energy Laser Joint Technology Office jointly sponsored this work.

165 citations


Journal ArticleDOI
TL;DR: In this article, a circularly polarized rectangular stair-shaped dielectric resonator antenna (DRA) is presented, which is excited by a narrow rectangular slot and rotated 45/spl deg/ with respect to the sides of the DRA to generate circular polarization.
Abstract: A circularly polarized rectangular stair shaped dielectric resonator antenna (DRA) is presented. The DRA is excited by a narrow rectangular slot and rotated 45/spl deg/ with respect to the sides of the DRA to generate circular polarization. A parametric study of the length to width ratio to optimize the axial ratio bandwidth is given. A 3 dB axial ratio bandwidth of 10.6% is achieved when the length to width ratio is 1.9.

161 citations


Journal ArticleDOI
TL;DR: By combining the techniques of optical TDM with polarisation multiplexing and DQPSK modulation format, 240 km transmission of 1.28 Tbit/s and 160 km transmission was performed in a single wavelength channel as mentioned in this paper.
Abstract: By combining the techniques of optical TDM with polarisation multiplexing and DQPSK modulation format, 240 km transmission of 1.28 Tbit/s and 160 km transmission of 2.56 Tbit/s has been performed in a single wavelength channel.

161 citations


Journal ArticleDOI
01 Jul 2006
TL;DR: The results show that cross polarization for the case of densely packed spheres can be significant and can be merely 6 to 8 dB below copolarization and that the active 13.5-GHz backscattering coefficients still have significant sensitivity to snow thickness even for snow thickness exceeding 1 m.
Abstract: Dense media radiative transfer (DMRT) theory is used to study the multiple-scattering effects in active microwave remote sensing Simplified DMRT phase matrices are obtained in the 1-2 frame The simplified expressions facilitate solutions of the DMRT equations and comparisons with other phase matrices First-order, second-order, and full multiple-scattering solutions of the DMRT equations are obtained To solve the DMRT equation, we decompose the diffuse intensities into Fourier series in the azimuthal direction Each harmonic is solved by the eigen-quadrature approach The model is applied to the active microwave remote sensing of terrestrial snow Full multiple-scattering effects are important as the optical thickness for snow at frequencies above 10 GHz often exceed unity The results are illustrated as a function of frequency, incidence angle, and snow depth The results show that cross polarization for the case of densely packed spheres can be significant and can be merely 6 to 8 dB below copolarization The magnitudes of the cross polarization are consistent with the experimental observations The results show that the active 135-GHz backscattering coefficients still have significant sensitivity to snow thickness even for snow thickness exceeding 1 m

Journal ArticleDOI
TL;DR: In this paper, a three-dimensional focus shaping technique using the combination of cylindrical polarization with binary diffractive optical element is proposed, where the energy density pattern at the vicinity of the focus can be tailored in three dimensions by appropriately adjusting the parameters of the cylinrical vector beam illumination, numerical aperture of the objective lens and the design of the binary diffraction optical element.

Journal ArticleDOI
TL;DR: In this article, single-walled carbon nanotube bundles were deposited onto glass substrates with controlled nanotubes orientation by two methods, self-assembly and dip-coating, generating dense and sparse carbon Nanotube films, respectively.

Journal ArticleDOI
TL;DR: The modulation of the Stokes parameters in Young's two-pinhole interference experiment with a random electromagnetic beam is analyzed and it is demonstrated that by using suitable wave plates the modulation in any Stokes parameter can be transformed into the form of intensity variation, and the electromagnetic degree of coherence can be obtained experimentally by four visibility measurements.
Abstract: We analyze the modulation of the Stokes parameters in Young's two-pinhole interference experiment with a random electromagnetic beam. We demonstrate that the electromagnetic (spectral) degree of coherence put forward in Opt. Lett.29, 328 (2004) [or its space-time analog in Opt. Express11, 1137 (2003)] is physically related to the contrasts of modulation in the four Stokes parameters. More explicitly, the electromagnetic degree of coherence is a measure of both the visibility of the intensity fringes and the modulation contrasts of the three polarization Stokes parameters. We also show that by using suitable wave plates the modulation in any Stokes parameter can be transformed into the form of intensity variation, and hence the electromagnetic degree of coherence can be obtained experimentally by four visibility measurements.

Journal ArticleDOI
TL;DR: A novel algorithm to overcome the issues related to the practical availability of finite-range birefringent components and to solve the requirement for endless stabilization is presented.
Abstract: The control of the state of polarization (SOP) of light remains one of the open issues in optical communications. In particular, the achievement of a stabilization of the SOP can find many applications in advanced optical communication systems: from the mitigation of polarization-mode dispersion to the development of novel multilevel modulation formats. In this paper, theoretical and experimental aspects of polarization stabilization are dealt with, and a novel algorithm to overcome the issues related to the practical availability of finite-range birefringent components and to solve the requirement for endless stabilization is also presented. A complete analysis of the control algorithm, based on the Jones matrix formalism, is also presented. The practical implementation of the polarization stabilizer is discussed, and experimental demonstrations based on liquid crystal and magnetooptical retarders are shown

Journal ArticleDOI
TL;DR: In this paper, the authors performed infrared imaging of the jet of the quasar 3C 273 at wavelengths of 3.6 and 5.8 μm with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope.
Abstract: We have performed infrared imaging of the jet of the quasar 3C 273 at wavelengths of 3.6 and 5.8 μm with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. When combined with the radio, optical, and X-ray measurements, the IRAC photometry of the X-ray-bright jet knots clearly shows that the optical emission is dominated by the high-energy emission component of the jet, not by the radio synchrotron component, as had been assumed to date. The high-energy component, represented by a power law from the optical through X-ray, may be due to a second synchrotron component or to inverse Compton scattering of ambient photons. In the former case, we argue that the acceleration of protons exceeding energies of Ep ~ 1016 eV or possibly even to Ep ~ 1019 eV would be taking place in the jet knots of 3C 273, assuming that the acceleration time is proportional to the particle gyroradius. In contrast, the inverse Compton model, into which highly relativistic Doppler beaming has to be incorporated, requires very low energy electrons of Ee ~ 1 MeV in the jet knots. The present polarization data in the radio and optical would favor the former interpretation in the case of the 3C 273 jet. Sensitive and detailed measurements of optical polarization are important in order to establish the radiation mechanism responsible for the high-energy emission. The present study offers new clues as to the controversial origin of the X-ray emission seen in many quasar jets.

Journal ArticleDOI
TL;DR: In this paper, the authors provide an accurate treatment of the mode conversion effect in magnetized NS atmosphere models, employing both the modal radiative transfer equations coupled with an accurate mode conversion probability at the vacuum resonance, and the full evolution equations for the photon Stokes parameters.
Abstract: Observations of surface emission from isolated neutron stars (NSs) provide unique challenges to theoretical modelling of radiative transfer in magnetized NS atmospheres. Recent work has demonstrated the critical role of vacuum polarization effects in determining NS spectra and polarization signals, in particular the conversion of photon modes (due to the 'vacuum resonance' between plasma and vacuum polarization) propagating in the density gradient of the NS atmosphere. Previous NS atmosphere models incorporated the mode conversion effect approximately, relying on transfer equations for the photon modes. Such treatments are inadequate near the vacuum resonance, particularly for magnetic field strengths around B ∼ B l ≃ 7 × 10 13 G, where the vacuum resonance occurs near the photosphere. In this paper, we provide an accurate treatment of the mode conversion effect in magnetized NS atmosphere models, employing both the modal radiative transfer equations coupled with an accurate mode conversion probability at the vacuum resonance, and the full evolution equations for the photon Stokes parameters. In doing so, we are able to quantitatively calculate the effects of vacuum polarization on atmosphere structure, emission spectra and beam patterns, and polarizations for the entire range of magnetic field strengths, B = 10 12 -10 15 G. In agreement with previous works, we find that for NSs with magnetic field strength B ≥ 2B l , vacuum polarization reduces the widths of spectral features, and softens the hard spectral tail typical of magnetized atmosphere models. For B ≤ B l /2, vacuum polarization does not change the emission spectra, but can significantly affect the polarization signals. Our new, accurate treatment of vacuum polarization is particularly important for quantitative modelling of NS atmospheres with 'intermediate' magnetic fields, B ≃ (0.5-2) B l . We provide fitting formulae for the temperature profiles for a suite of NS atmosphere models with different field strengths, effective temperatures and chemical compositions (ionized H or He). These analytical profiles are useful for direct modelling of various observed properties of NS surface emission. As an example, we calculate the observed intensity and polarization light curves from a rotating NS hotspot, taking into account the evolution of photon polarization in the magnetosphere. We show that vacuum polarization induces a unique energy-dependent linear polarization signature, and that circular polarization can be generated in the magnetosphere of rapidly rotating NSs. We discuss the implications of our results to recent observations of thermally emitting isolated NSs and magnetars, as well as the prospects of future spectral and polarization observations.

Journal ArticleDOI
TL;DR: In this article, the temperature and concentration dependence of nonphotochemical laser-induced nucleation (NPLIN) was studied in aqueous glycine solutions at wavelengths of 532 and 1064 nm, using linearly, circularly, and elliptically polarized light.
Abstract: The temperature and concentration dependence of nonphotochemical laser-induced nucleation (NPLIN) was studied in aqueous glycine solutions at wavelengths of 532 and 1064 nm, using linearly, circularly, and elliptically polarized light. We observed a narrow supersaturation window (c/c0 = 1.45−1.55, where c is the solution molality, and c0 is the molality of a saturated solution) for “polarization switching”, i.e., different polarizations producing different polymorphs. We also observed that, within this window, a small range of ellipticities near unity could induce the nucleation of the α-polymorph and that this range depended on supersaturation. Similar “polarization switching” behavior was observed at wavelengths of 1064 and 532 nm, although the supersaturation window became narrower at lower laser intensities at both wavelengths. Order-parameter ellipsoids and triangles based on optical Kerr alignment are presented to aid in the interpretation of the experimental results.

Journal ArticleDOI
TL;DR: A spectral interference law is derived that governs the behavior of the four Stokes parameters in Young's two-pinhole experiment with a random electromagnetic beam and three new contrast parameters are introduced that describe the interference-induced changes in the field's state of partial polarization.
Abstract: We derive a spectral interference law that governs the behavior of the four Stokes parameters in Young's two-pinhole experiment with a random electromagnetic beam. In addition to the visibility of intensity fringes, we introduce three new contrast parameters that describe the interference-induced changes in the field's state of partial polarization. The polarization modulation depends on the electric field correlations at the pinholes and is closely related to the two-point Stokes parameters. The results are expected to be particularly useful in polarization interferometry and electromagnetic coherence theory. The formalism is demonstrated with specific examples.

Proceedings ArticleDOI
TL;DR: In this article, the mesogen polarization gratings are used to measure all four Stokes parameters of a broad spectrum of wavelengths, including visible and infrared, at relatively high speed (MHz or more).
Abstract: The measurement of complete polarimetric parameters for a broad spectrum of wavelengths is challenging because of the multi-dimensional nature of the data and the need to chromatically separate the light under test. As a result, current methods for spectropolarimetry and imaging polarimetry are limited because they tend to be complex and/or relatively slow. Here we experimentally demonstrate an approach to measure all four Stokes parameters using three polarization gratings and four simultaneous intensity measurements, with potential to dramatically impact the varied fields of air/space-borne remote sensing, target detection, biomedical imaging/diagnosis, and telecommunications. We have developed reactive mesogen polarization gratings using simple spin-casting and holography techniques, and used them to implement a potentially revolutionary detector capable of simultaneous measurement of full polarization information at many wavelengths with no moving or tunable elements. This polarimeter design not only enables measurements over a likely bandwidth of up to 70% of the center wavelength, it is also capable of measurements at relatively high speed (MHz or more) limited only by the choice of photo-detectors and processing power of the system. The polarization gratings themselves manifest nearly ideal behavior, including diffraction efficiencies of greater than 99%, strong polarization sensitivity of the first diffraction orders, very low incoherent scattering, and suitability for visible and infrared light. Due to its simple and compact design, simultaneous measurement process, and potential for preserving image registration, this spectropolarimeter should prove an attractive alternative to current polarization detection and imaging systems.

Journal ArticleDOI
TL;DR: In this article, the performance of the polarization-nulling technique was analyzed and several techniques to overcome the effect of nonlinear birefringence in a highly nonlinear transmission link.
Abstract: The polarization-nulling technique utilizes the different properties of optical signal and amplified spontaneous emission (ASE) noise for accurate monitoring of the optical-signal-to-noise ratio (OSNR) in dynamic optical networks. However, the performance of this technique is bound to be deteriorated if the signal is depolarized by polarization-mode dispersion and/or nonlinear birefringence or the ASE noise is partially polarized due to polarization-dependent loss (PDL) in the transmission link. The authors analyze these effects on the performance of the polarization-nulling technique and introduce several techniques to overcome these problems. These improved versions of the polarization-nulling techniques could monitor the OSNR with accuracy of better than plusmn1 dB, even when the differential group delay is as large as 60 ps. These techniques could also negate the effect of the signal depolarization caused by nonlinear birefringence in a highly nonlinear transmission link. The effect of the partially polarized ASE noise due to PDL is found to be not severe in most cases, as long as the PDL/span is smaller than 0.2 dB. To verify the possibility of using the polarization-nulling technique in real systems, the OSNR of the wavelength-division-multiplexed (WDM) signals transmitted through a 120-km-long aerial fiber link is measured for one week. No significant degradation in the monitoring accuracy is observed during this long-term measurement. In addition, the performance of the polarization-nulling technique in an ultralong-haul transmission link is evaluated by using a 640-km-long recirculating loop. The results show that this technique could accurately measure the OSNR in the transmission link longer than 3200 km. From these results, the authors conclude that the polarization-nulling technique is well suited for monitoring the OSNR in dynamic WDM networks

Journal ArticleDOI
TL;DR: In this article, it is shown that extraordinary optical transmission through perforated metallic films is possible for s-polarization, and numerical simulations confirm that the existence of a surface wave, whatever its nature, is responsible for the optical transmission phenomenon.
Abstract: It is shown that extraordinary optical transmission through perforated metallic films is possible for s-polarization. Although surface plasmons do not exist for this polarization, their role can be played by a wave sustained by a thin dielectric layer on top of the metallic film. The numerical simulations presented here confirm that the existence of a surface wave, whatever its nature, is responsible for the extraordinary optical transmission phenomenon.

Journal ArticleDOI
TL;DR: In this paper, the authors performed infrared imaging of the jet of the quasar 3C 273 at wavelengths 3.6 and 5.8 microns with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope.
Abstract: We have performed infrared imaging of the jet of the quasar 3C 273 at wavelengths 3.6 and 5.8 microns with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. When combined with the radio, optical and X-ray measurements, the IRAC photometry clearly shows that the optical emission is dominated by the high-energy component of the jet, not by the radio synchrotron component, as had been assumed to date. The high-energy component may be due to a second synchrotron component or to IC scattering of ambient photons. In the former case, we argue that the acceleration of protons exceeding 10^16 eV or possibly even to 10^19 eV would be taking place in the jet. In contrast, the IC model, into which highly relativistic Doppler beaming has to be incorporated, requires very low-energy electrons (~ 1 MeV). The present polarization data in the radio and optical would favor the former interpretation in the case of the 3C 273 jet. Sensitive and detailed measurements of optical polarization are important to establish the radiation mechanism responsible for the high-energy emission. The present study offers new clues as to the controversial origin of the X-ray emission seen in many quasar jets.

Journal ArticleDOI
TL;DR: A polarization-independent optical directional coupler based on slot waveguides is proposed and analyzed by using rigorous full-vectorial analysis methods based on a finite-element scheme to make the coupling length for quasi-TE modes become equal to that for semi-TM modes.
Abstract: A polarization-independent optical directional coupler based on slot waveguides is proposed and analyzed by using rigorous full-vectorial analysis methods based on a finite-element scheme. Properly choosing materials and structural parameters makes the coupling length for quasi-TE modes become equal to that for quasi-TM modes. Tolerances to operating wavelength and structural parameters are also discussed. The proposed coupler can be used for highly integrated optical circuits without polarization diversity schemes.

Journal ArticleDOI
TL;DR: This work introduces a method to detect and extract latent fingerprint images without applying any powder or chemicals on the object, based on the optical phenomena of polarization and specular reflection together with the physiology of fingerprint formation.
Abstract: In forensic science the finger marks left unintentionally by people at a crime scene are referred to as latent fingerprints. Most existing techniques to detect and lift latent fingerprints require application of a certain material directly onto the exhibit. The chemical and physical processing applied to the fingerprint potentially degrades or prevents further forensic testing on the same evidence sample. Many existing methods also have deleterious side effects. We introduce a method to detect and extract latent fingerprint images without applying any powder or chemicals on the object. Our method is based on the optical phenomena of polarization and specular reflection together with the physiology of fingerprint formation. The recovered image quality is comparable to existing methods. In some cases, such as the sticky side of tape, our method shows unique advantages.

Journal ArticleDOI
TL;DR: The spectral polarization of an ultrashort pulse is fully controlled by a novel pulse shaper design, including three liquid-crystal spatial light modulator arrays at three different orientations, with possible applications in multidimensional spectroscopy, coherent control, and ultrafast polarization gating.
Abstract: The spectral polarization of an ultrashort pulse is fully controlled by a novel pulse shaper design, including three liquid-crystal spatial light modulator arrays at three different orientations. The added degree of controllability permits generation of previously unattainable pulse shapes, with possible applications in multidimensional spectroscopy, coherent control, and ultrafast polarization gating.

Journal ArticleDOI
TL;DR: In this paper, a spherical glass cell of 3 mm diameter containing Cs metal with inner walls coated with paraffin was used for nonlinear magneto-optical-rotation signals with frequency and amplitude-modulated laser light.
Abstract: Dynamic nonlinear magneto-optical-rotation signals with frequency- and amplitude-modulated laser light have been observed and investigated with a spherical glass cell of 3 mm diameter containing Cs metal with inner walls coated with paraffin. Intrinsic Zeeman relaxation rates of γ/(2π)≈20 Hz and lower have been observed. Favorable prospects of using millimeter-scale coated cells in portable magnetometers and secondary frequency references are discussed.

Proceedings ArticleDOI
01 Dec 2006
TL;DR: In this paper, the authors demonstrate transmission and demodulation of 40Gbit/s per wavelength data, using 10Gbaud polarisation multiplexed QPSK, including carrier recovery and equalisation of all linear impairments, including chromatic dispersion and polarisation mode dispersion.
Abstract: We demonstrate transmission and demodulation of 40Gbit/s per wavelength data, using 10Gbaud polarisation multiplexed QPSK. The digital coherent receiver includes carrier recovery and equalisation of all linear impairments, including chromatic dispersion and polarisation mode dispersion.

Proceedings ArticleDOI
TL;DR: In this article, an on-axis, vibration insensitive, polarization Fizeau interferometer is realized through the use of a novel pixelated mask spatial carrier phase shifting technique in conjunction with a low coherence source and a polarization delay-line.
Abstract: An on-axis, vibration insensitive, polarization Fizeau interferometer is realized through the use of a novel pixelated mask spatial carrier phase shifting technique in conjunction with a low coherence source and a polarization delay-line. In this arrangement, coherence is used to effectively separate out the orthogonally polarized test and reference beam components for interference. With both the test and the reference beams on-axis, the common path cancellation advantages of the Fizeau interferometer are maintained. The interferometer has the unique ability to isolate and measure any surface that is substantially normal to the optical axis of the cavity. Additionally, stray light interference is substantially reduced due to the source's short coherence. An expression for the fringe visibility on-axis is derived and compared with that of a standard Fizeau. Using a 15 mW source, the maximum camera shutter speed, used when measuring a 4% reflector, was 150 usec, resulting in very robust vibration insensitivity. We experimentally demonstrate the measurement of both sides of a thin glass plate without the need to modify the plate between measurements. Experimental results show the performance of this new interferometer to be within the specifications of commercial phase shifting interferometers.

Journal ArticleDOI
TL;DR: In this article, the use of bidirectional pumping and collinear propagation in type-II phase-matched periodically poled KTiOPO4 to achieve efficient generation of polarization-entangled photons via spontaneous parametric downconversion was reviewed.
Abstract: We review the use of bidirectional pumping and collinear propagation in type-II phase-matched periodically poled KTiOPO4 to achieve efficient generation of polarization-entangled photons via spontaneous parametric downconversion. The advantages of this approach are fully exploited in our optimized polarization Sagnac interferometric source. Its measured flux of 4700 polarization-entangled photon pairs/s per milliwatt of pump power in a 1-nm bandwidth exhibited 99% quantum-interference visibility. We also present a plane-wave Gaussian state theory for continuous-wave spontaneous parametric downconversion. This formulation affords the complete description of multiple-pair emissions that is needed for quantum communication analyses while reducing to the usual biphoton-state description at low generation rates.