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Julia P Dark, Arnold D Kim
We establish a quantitative theory of circular polarization memory, which is the unexpected persistence of the incident circular polarization state in a strongly scattering medium. Using an asymptotic analysis of the three-dimensional vector radiative transfer equation (VRTE) in the limit of strong scattering, we find that circular polarization memory must occur in a boundary layer near the portion of the boundary on which polarized light is incident. The boundary layer solution satisfies a one-dimensional conservative scattering VRTE...
September 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Sunggoo Cho
Parabasal theory is a technique in geometrical optics, which describes the behavior of light rays located near some defined base ray rather than the optical axis. In this work, we are concerned with parabasal rays, which lie in a sufficiently small neighborhood of a chief ray and develop some formulas for the parabasal quantities of the chief ray. The parabasal quantities of a chief ray are shown to be intimately related to the coefficients of the first-order differential equations of the chief ray. Using the relations, we derive parabasal formulas containing parabasal refractive indices and parabasal powers from the first-order differential equations...
September 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Paula Ortega-Vidals, Omar de Jesús Cabrera-Rosas, Ernesto Espíndola Ramos, Salvador Alejandro Juárez Reyes, Israel Julían Macías, Gilberto Silva-Ortigoza, Ramón Silva-Ortigoza, Citlalli Teresa Sosa-Sánchez
The aim of the present work is to obtain an integral representation of the field associated with the refraction of a plane wave by an arbitrary surface. To this end, in the first part we consider two optical media with refraction indexes n1 and n2 separated by an arbitrary interface, and we show that the optical path length, ϕ, associated with the evolution of the plane wave is a complete integral of the eikonal equation in the optical medium with refraction index n2. Then by using the k function procedure introduced by Stavroudis, we define a new complete integral, S, of the eikonal equation...
September 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Mohammad Mahdi Taskhiri, Mohammad Khalaj Amirhosseini
This paper presents a novel inhomogeneous hemispherical dielectric lens. The proposed lens is designed based on the ray inserting method (RIM). Applying this approach, a uniform distribution of the rays' end points over the lens plane aperture is achieved while lens matching to the environment refractive index is perfectly fulfilled. We can change the antenna features such as sidelobe level and gain by controlling the end point of each ray propagated through the hemispherical lens. The refractive index of the designed hemispherical inhomogeneous lens is derived and it is validated using COMSOL Multiphysics...
July 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Chung-Yu Tsai
A refractive laser beam shaper comprising two free-form profiles is presented. The profiles are designed using a free-form profile construction method such that each incident ray is directed in a certain user-specified direction or to a particular point on the target surface so as to achieve the required illumination distribution of the output beam. The validity of the proposed design method is demonstrated by means of ZEMAX simulations. The method is mathematically straightforward and easily implemented in computer code...
July 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Yangyundou Wang, Shenggang Yan, Ari T Friberg, David Kuebel, Taco D Visser
We study the field that is produced by a paraxial refractive axicon lens. The results from geometrical optics, scalar wave optics, and electromagnetic diffraction theory are compared. In particular, the axial intensity, the on-axis effective wavelength, the transverse intensity, and the far-zone field are examined. A rigorous electromagnetic diffraction analysis shows that the state of polarization of the incident beam strongly affects the transverse intensity distribution, but not the intensity distribution in the far zone...
July 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Zahra Vali, Asghar Gholami, Zabih Ghassemlooy, David G Michelson, Masood Omoomi, Hamed Noori
Turbulence affects the performance of underwater wireless optical communications (UWOC). Although multiple scattering and absorption have been previously investigated by means of physical simulation models, still a physical simulation model is needed for UWOC with turbulence. In this paper, we propose a Monte Carlo simulation model for UWOC in turbulent oceanic clear water, which is far less computationally intensive than approaches based on computational fluid dynamics. The model is based on the variation of refractive index in a horizontal link...
July 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Cristian E Gutiérrez, Luca Pallucchini, Eric Stachura
This paper provides a mathematical approach to study metasurfaces in nonflat geometries. Analytical conditions between the curvature of the surface and the set of refracted directions are introduced to guarantee the existence of phase discontinuities. The approach contains both the near and far field cases. A starting point is the formulation of a vector Snell's law in the presence of abrupt discontinuities on the interfaces.
July 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Jeremy P Bos, V S Rao Gudimetla, Jason D Schmidt
We derive a generalized expression for the differential piston phase variance in non-Kolmogorov turbulence. Specifically, our result applies in the case where index of refraction is described by a power-law medium with an exponent between 0 and 1. Kolmogorov assumptions of homogeneity and isotropy are maintained. After some development, our expression is derived using the Mellin-transform techniques and may be generalized to other forms for the three-dimensional index of refraction turbulence power spectrum...
August 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Razvigor Ossikovski, Oriol Arteaga, Jérémy Vizet, Enric Garcia-Caurel
We show, both analytically and experimentally, that under common experimental conditions the interference pattern produced in a classic Young's double-slit experiment is indistinguishable from that generated by means of a doubly refracting uniaxial crystal whose optic axis makes a skew angle with the light propagation direction. The equivalence between diffraction and crystal optics interference experiments, taken for granted by Arago and Fresnel in their pioneering research on the interference of polarized light beams, is thus rigorously proven...
August 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Jia Li, Olga Korotkova
Deterministic mode representation (DMR) is introduced for a three-dimensional random medium with a statistically stationary refractive index distribution. The DMR allows for the designing and fine tuning of novel random media by adjusting the weights of individual deterministic modes. To illustrate its usefulness, we have applied the decomposition to the problem of weak light scattering from a Gaussian Schell-model medium. In particular, we have shown how individual deterministic modes of the medium contribute to the scattered far-field spectral density distribution...
June 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Dajun Liu, Hongming Yin, Guiqiu Wang, Yaochuan Wang
The cross-spectral density function of a partially coherent Lorentz beam propagating in uniaxial crystal orthogonal to the optical axis is obtained, and the evolution properties and the spectral degree of coherence for a partially coherent Lorentz beam in uniaxial crystal are illustrated by using numerical examples. The influence of coherence length and the ratio of refractive index ne/no on the normalized intensity and spectral degree of coherence for a partially coherent Lorentz beam are analyzed in detail...
June 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Sudhakar Prasad
We present an extended Taylor frozen-flow model for the statistics of the spatiotemporal disturbances of the index of refraction of air and the phase of an optical beam propagated through the turbulent boundary and shear layers in a high-Reynolds-number flow. By incorporating rapid random fluctuations of the flow velocity about a mean convection velocity and an anisotropic spatial power spectrum for the index of refraction, we calculate both the short-delay temporal structure function and the power spectral density of these disturbances...
June 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Chi Lok Wong, Marissa Chua, Heather Mittman, Li Xian Choo, Hann Qian Lim, Malini Olivo
In this paper, we present a phase-intensity surface plasmon resonance (SPR) biosensor and demonstrate its use for avian influenza A (H5N1) antibody biomarker detection. The sensor probes the intensity variation produced by the steep phase response at surface plasmon excitation. The prism sensor head is fixed between a pair of polarizers with a perpendicular orientation angle and a forbidden transmission path. At SPR, a steep phase change is introduced between the p- and s-polarized light, and this rotates the polarization ellipse of the transmission beam...
October 16, 2017: Sensors
Wei Xu, Jia Shi, Xianchao Yang, Degang Xu, Feng Rong, Junfa Zhao, Jianquan Yao
A relative humidity (RH) sensor based on single-mode-no-core-single-mode fiber (SNCS) structure is proposed and experimentally demonstrated. The agarose gel is coated on the no-core fiber (NCF) as the cladding, and multimode interference (MMI) occurs in the SNCS structure. The transmission spectrum of the sensor is modulated at different ambient relative humidities due to the tunable refractive index property of the agarose gel film. The relative humidity can be measured by the wavelength shift and intensity variation of the dip in the transmission spectra...
October 16, 2017: Sensors
Hye-Na Kim, Sanaz Vahidinia, Amanda L Holt, Alison M Sweeney, Shu Yang
It will be ideal to deliver equal, optimally efficient "doses" of sunlight to all cells in a photobioreactor system, while simultaneously utilizing the entire solar resource. Backed by the numerical scattering simulation and optimization, here, the design, synthesis, and characterization of the synthetic iridocytes that recapitulated the salient forward-scattering behavior of the Tridacnid clam system are reported, which presents the first geometric solution to allow narrow, precise forward redistribution of flux, utilizing the solar resource at the maximum quantum efficiency possible in living cells...
October 16, 2017: Advanced Materials
Alejandro Leal-Duaso, Pascual Pérez, José A Mayoral, Elisabet Pires, José I García
In this work we report the preparation of mixtures of several alkyl glyceryl ethers, as hydrogen bond donor compounds, with two ammonium salts, choline chloride and N,N,N-triethyl-2,3-dihydroxypropan-1-aminium chloride. The stability of the mixtures at different molar ratios and temperatures has been evaluated in order to determine the formation of low melting mixtures. Liquid and stable mixtures have been characterized and their physico-chemical properties such as density, viscosity, refractive index, conductivity and surface tension have been measured in the temperature range of 293...
October 16, 2017: Physical Chemistry Chemical Physics: PCCP
Meng-Sheng Lee, I-Lun Tsai, Ching-Yao Tsai, Li-Lin Kuo, Shiow-Wen Liou, Lin-Chung Woung
Compared with conventional penetrating keratoplasty, Descemet's stripping automated endothelial keratoplasty (DSAEK) more effectively maintain global integrity and rapid vision rehabilitation with less ocular surface disorders in patients with endothelial dysfunction. Here, we report a case of a 76-year-old woman who experienced opacification of a hydrophilic intraocular lens (IOL) approximately 10 months after DSAEK. The patient with no history of systemic disease developed pseudophakic bullous keratopathy in the right eye 2 years after undergoing cataract surgery...
July 2017: Taiwan Journal of Ophthalmology
Jenchieh Weng, I-Lun Tsai, Li-Lin Kuo, Ching-Yao Tsai, Lin-Chung Woung, Ya-Chuan Hsiao
BACKGROUND/PURPOSE: Topical atropine treatment is generally accepted to retard the progression of myopia, but it is associated with side effects such as photophobia and elevation of intraocular pressure (IOP). IOP measurements in children are challenging. The traditional applanation tonometry by direct contact with the cornea will require patient's cooperation. The rebound tonometer, using a dynamic electromechanical method for measuring IOP, shows good correlation with traditional tonometry...
July 2017: Taiwan Journal of Ophthalmology
Srijana Adhikari, Ujjowala Shrestha, Mohan K Shrestha, Manish Paudyal, Bijaya Thapa, Murari Shrestha
PURPOSE: The Nepal Pediatric Ocular Diseases Study (NPODS) was a 3-year (January 2012-December 2014) longitudinal study carried out in three ecological regions of Nepal to understand the magnitude of the problems of childhood ocular morbidity and blindness. Based on the results of this study, a second phase of NPODS was undertaken to understand the risk factors associated with childhood ocular diseases. This paper analyzes environmental factors. METHOD: This was a nested case-control study with study population selected from the same cohort of children included in the baseline survey of NPODS...
October 14, 2017: International Ophthalmology
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