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https://www.readbyqxmd.com/read/28438008/birefringent-masks-that-are-optimal-for-generating-bottle-fields
#1
Anthony Vella, Hippolyte Dourdent, Lukas Novotny, Miguel A Alonso
An optical bottle field containing a three-dimensional intensity null at the focal point can be generated by placing a spatially inhomogeneous birefringent mask at the pupil of an aplanatic high-NA focusing system. We derive the optimal birefringence distribution for which a uniformly polarized input beam is converted into a bottle field with the sharpest possible null in intensity. We show that a stress engineered optical (SEO) window, which has a radially varying retardance, followed by a half-wave plate, performs nearly as well as the optimal solution...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28438004/autofocusing-airy-beams-generated-by-all-dielectric-metasurface-for-visible-light
#2
Qingbin Fan, Daopeng Wang, Pengcheng Huo, Zijie Zhang, Yuzhang Liang, Ting Xu
Conventional method to generate autofocusing Airy (AFA) beam involves the optical Fourier transform (FT) system, which has a fairly long working distance due to the focal length of FT lens, presence of spatial light modulator (SLM) and auxiliary total reflection mirrors. Here, we propose an extremely compact design to generate high-efficiency AFA beam at visible frequency by using metasurface which is composed of a single layer array of amorphous titanium dioxide (TiO<sub>2</sub>) elliptical nanofins sitting on the fused-silica substrate...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28438000/development-of-limited-view-and-three-dimensional-reconstruction-method-for-analysis-of-electrohydrodynamic-jetting-behavior
#3
Yeonghyeon Gim, Dong Ho Shin, Do Yoon Moh, Han Seo Ko
For an electrohydrodynamic (EHD) jet, variables such as the direction of the meniscus and the ejection stability need to be analyzed. Thus, the EHD jet should be observed three-dimensionally (3D) because the variables can only be obtained in the 3D field, especially in unstable modes. However, if the 3D field is reconstructed from multi-directional binary images, eliminating reconstruction errors caused by invisible areas is almost impossible, even when using a tomographic technique. To solve this problem, a new 3D reconstruction method including an ellipse estimation was developed in this study...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437998/specific-distribution-of-the-light-captured-by-silver-nanowire
#4
Yingfeng Li, Younan Luo, Wenjian Liu, Mengqi Cui, Jerry Kumar, Bing Jiang, Lihua Chu, Meicheng Li
The silver nanowire (AgNW) has excellent light capture ability, showing great prospects in many fields. Based on discrete dipole approximation simulations, it is found that the captured light can be subdivided into three parts: the near-field light occupies ~27.3%, mainly confined around the nanowire with a distance <20nm; the far-field part occupies ~59.6%, showing a dramatic conical distribution; and ~13.1% is ohmically absorbed. These insights are helpful to estimate the limited performance of AgNW-based device utilizing each subdivision, and locate the functional zone...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437992/a-large-airborne-survey-of-earth-s-visible-infrared-spectral-dimensionality
#5
David R Thompson, Joseph W Boardman, Michael L Eastwood, Robert O Green
The intrinsic spectral dimensionality indicates the observable degrees of freedom in Earth's solar-reflected light field, quantifying the diversity of spectral content accessible by visible and infrared remote sensing. The solar-reflected regime spans the 0.38 - 2.5 μm interval, and is captured by a wide range of current and planned instruments on both airborne and orbital platforms. To date there has been no systematic study of its spectral dimensionality as a function of space, time, and land cover. Here we report a multi-site, multi-year statistical survey by NASA's "Classic" Airborne Visible Near InfraRed Spectrometer (AVIRIS-C)...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437991/high-speed-triangular-pattern-phase-shifting-3d-measurement-based-on-the-motion-blur-method
#6
Huijie Zhao, Xiaochun Diao, Hongzhi Jiang, Xudong Li
Recent advancements in 3D measurement technologies have increased the urgency of requiring high-speed 3D measurement in many fields. This study presents a novel four-step triangular pattern phase-shifting 3D measurement using the motion blur method, which combines the advantages of phase-shifting methods. To comply with the high speed requirement, binary coded triangular patterns are projected and could dither vertically. Therefore, the image captured by the camera is blurred into grayscale-intensity triangular patterns, which can be used for phase unwrapping and 3D reconstruction...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437988/selective-excitation-of-surface-plasmon-modes-propagating-in-ag-nanowires
#7
Mingxia Song, Jean Dellinger, Olivier Demichel, Mickaël Buret, Gérard Colas Des Francs, Douguo Zhang, Erik Dujardin, Alexandre Bouhelier
Surface plasmon modes propagating in metal nanowires are conveniently excited by focusing a laser beam on one extremity of the nanowire. We find that the precise positioning of the nanowire inside the focal region drastically influences the excitation efficiency of the different SPP modes sustained by the plasmonic waveguide. We demonstrate a spatially selective excitation of bound and leaky surface plasmon modes with excitation maps that strongly depend on the orientation of the incident linear polarization...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437987/source-diversity-for-transport-of-intensity-phase-imaging
#8
Tonmoy Chakraborty, Jonathan C Petruccelli
The transport of intensity equation (TIE) is a phase retrieval method that relies on measurements of the intensity of a paraxial field under propagation between two or more closely spaced planes. A limitation of TIE is its susceptibility to low frequency noise artifacts in the reconstructed phase. Under Köhler illumination, when both illumination power and exposure time are limited, the use of larger sources can improve low-frequency performance although it introduces blurring. Appropriately combining intensity measurements taken with a diversity of source sizes can improve both low- and high-frequency performance in phase reconstruction...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437985/scattering-of-surface-plasmon-polaritons-at-a-planar-interface-by-an-embedded-dielectric-nanocube
#9
Seojun Lee, Hyungchae Kim, Jongcheon Lee, Changsoon Kim
We investigate scattering of surface plasmon polaritons (SPPs) at a planar metal-dielectric interface by a dielectric nanocube embedded in the metal layer using finite element method-based simulations. The scattering characteristics of the embedded nanocube, such as the scattering and absorption cross sections, far-field scattering patterns, reflectance, and transmittance, are calculated as functions of the wavelength of the incident SPP waves in the visible range. The main features of the characteristics are explained in connection with the excitation of plasmonic eigenmodes of the embedded nanocube...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437972/integration-of-bow-tie-plasmonic-nano-antennas-on-tapered-fibers
#10
Abdul Khaleque, Evgeny G Mironov, Jonas H Osório, Ziyuan Li, Cristiano M B Cordeiro, Liming Liu, Marcos A R Franco, Jong-Leng Liow, Haroldo T Hattori
In this article, a new and flexible approach to control the electric field enhancement of bow-tie nano-antennas by integrating them on the lateral of a tapered optical fiber is proposed. The device is driven by a Q-switched laser and the performance of a fabricated nano-antenna in a quartz slide is tested by a Surface Enhanced Raman Scattering (SERS) experiment. A refractive index sensing experiment is also performed and a sensitivity of (240 ± 30) nm/RIU is found in the 1.33-1.35 index range.
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437970/cmos-compatible-broadband-co-propagative-stationary-fourier-transform-spectrometer-integrated-on-a-silicon-nitride-photonics-platform
#11
Xiaomin Nie, Eva Ryckeboer, Gunther Roelkens, Roel Baets
We demonstrate a novel type of Fourier Transform Spectrometer (FTS) that can be realized with CMOS compatible fabrication techniques. This FTS contains no moving components and is based on the direct detection of the interferogram generated by the interference of the evanescent fields of two co-propagating waveguide modes. The theoretical analysis indicates that this type of FTS inherently has a large bandwidth (>100 nm). The first prototype that is integrated on a Si<sub>3</sub>N<sub>4</sub> waveguide platform is demonstrated and has an extremely small size (0...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437969/experimental-generation-of-complex-optical-fields-for-diffraction-limited-optical-focus-with-purely-transverse-spin-angular-momentum
#12
Jian Chen, Chenhao Wan, Lingjiang Kong, Qiwen Zhan
We demonstrate a method to generate complex optical fields at the pupil plane of a high numerical aperture (NA) objective lens for the creation of diffraction limited optical focus with purely transverse spin angular momentum. The complex optical fields are analytically deduced through reversing the radiated patterns from two electric dipoles, which are located at the focal point of the high NA lens and oscillate respectively in x- and z- directions with phase difference of π/2. The derived fields can be experimentally created with a vectorial optical field generator...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437967/design-of-see-through-near-eye-display-for-presbyopia
#13
Yishi Wu, Chao Ping Chen, Lei Zhou, Yang Li, Bing Yu, Huayi Jin
We propose a compact design of see-through near-eye display that is dedicated to presbyopia. Our solution is characterized by a plano-convex waveguide, which is essentially an integration of a corrective lens and two volume holograms. Its design rules are set forth in detail, followed by the results and discussion regarding the diffraction efficiency, field of view, modulation transfer function, distortion, and simulated imaging.
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437948/uv-sensitive-superconducting-nanowire-single-photon-detectors-for-integration-in-an-ion-trap
#14
D H Slichter, V B Verma, D Leibfried, R P Mirin, S W Nam, D J Wineland
We demonstrate superconducting nanowire single photon detectors with 76 ± 4% system detection efficiency at a wavelength of 315 nm and an operating temperature of 3.2 K, with a background count rate below 1 count per second at saturated detection efficiency. We propose integrating these detectors into planar surface electrode radio-frequency Paul traps for use in trapped ion quantum information processing. We operate detectors integrated into test ion trap structures at 3.8 K both with and without typical radio-frequency trapping electric fields...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437947/hard-x-ray-scanning-imaging-achieved-with-bonded-multilayer-laue-lenses
#15
Xiaojing Huang, Weihe Xu, Evgeny Nazaretski, Nathalie Bouet, Juan Zhou, Yong S Chu, Hanfei Yan
We report scanning hard x-ray imaging with a monolithic focusing optic consisting of two multilayer Laue lenses (MLLs) bonded together. With optics pre-characterization and accurate control of the bonding process, we show that a common focal plane for both MLLs can be realized at 9.317 keV. Using bonded MLLs, we obtained a scanning transmission image of a star test pattern with a resolution of 50 × 50 nm<sup>2</sup>. By applying a ptychography algorithm, we obtained a probe size of 17 × 38 nm<sup>2</sup> and an object image with a resolution of 13 × 13 nm<sup>2</sup>...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437941/effect-of-scattering-on-coherent-anti-stokes-raman-scattering-cars-signals
#16
Janaka C Ranasinghesagara, Giuseppe De Vito, Vincenzo Piazza, Eric O Potma, Vasan Venugopalan
We develop a computational framework to examine the factors responsible for scattering-induced distortions of coherent anti-Stokes Raman scattering (CARS) signals in turbid samples. We apply the Huygens-Fresnel wave-based electric field superposition (HF-WEFS) method combined with the radiating dipole approximation to compute the effects of scattering-induced distortions of focal excitation fields on the far-field CARS signal. We analyze the effect of spherical scatterers, placed in the vicinity of the focal volume, on the CARS signal emitted by different objects (2μm diameter solid sphere, 2μm diameter myelin cylinder and 2μm diameter myelin tube)...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437940/rydberg-atom-based-radio-frequency-electrometry-using-frequency-modulation-spectroscopy-in-room-temperature-vapor-cells
#17
Santosh Kumar, Haoquan Fan, Harald Kübler, Akbar J Jahangiri, James P Shaffer
Rydberg atom-based electrometry enables traceable electric field measurements with high sensitivity over a large frequency range, from gigahertz to terahertz. Such measurements are particularly useful for the calibration of radio frequency and terahertz devices, as well as other applications like near field imaging of electric fields. We utilize frequency modulated spectroscopy with active control of residual amplitude modulation to improve the signal to noise ratio of the optical readout of Rydberg atom-based radio frequency electrometry...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437939/exploiting-high-order-phase-shift-keying-modulation-and-direct-detection-in-silicon-photonic-systems
#18
Jie You, Nicolae C Panoiu
A computational approach to evaluate the bit-error ratio (BER) in silicon photonic systems employing high-order phase-shift keying (PSK) modulation formats is presented. Specifically, the investigated systems contain a silicon based optical interconnect, namely a strip silicon photonic waveguide or a silicon photonic crystal waveguide, and direct-detection receivers suitable to detect PSK and amplitude-shaped PSK signals. The superposition of a PSK signal and complex additive white Gaussian noise passes through the optical interconnect and subsequently through two detection-branch receivers...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437933/optical-wave-parameters-for-spatially-dispersive-and-anisotropic-nanomaterials
#19
Andriy Shevchenko, Markus Nyman, Ville Kivijärvi, Matti Kaivola
Spatial dispersion is an intriguing property of essentially all nanostructured optical media. In particular, it makes optical waves with equal frequencies and polarizations have different wavelengths, if they propagate in different directions. This can offer new approaches to control light radiation and propagation. Spatially dispersive nanomaterials, such as metamaterials, are often treated in terms of wave parameters, such as refractive index and impedance retrieved from reflection and transmission coefficients of the material at each incidence angle...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437927/precision-measurement-of-magnetic-field-based-on-the-transient-process-in-a-k-rb-sup-21-sup-ne-co-magnetometer
#20
Wei Quan, Kai Wei, Hairong Li
We demonstrate a novel method of measuring magnetic field based on the transient signal of the K-Rb-<sup>21</sup>Ne co-magnetometer operating in nuclear spin magnetization self-compensation magnetic field regime. The operation condition for self-compensation magnetic field by nuclear spin magnetization of <sup>21</sup>Ne in steady state is presented. We characterize the dynamics of the coupled spin ensembles by a set of Bloch equations, and formulate the expression of transient output signal...
April 17, 2017: Optics Express
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