Accepted papers to appear in an upcoming issue
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Focus correction in apodized system with spherical aberration
Paula Bernal-Molina, José Castejón-Mochón, Arthur Bradley, and Norberto Lopez-Gil
Doc ID: 239680 Received 24 Apr 2015; Accepted 04 Jul 2015; Posted 06 Jul 2015 View: PDF
Abstract: We performed a theoretical and computational analysis of the through-focus axial intensity in a system with a Gaussian amplitude pupil function and fourth- and sixth-order spherical aberration. Two cases are analyzed: low aberrated systems, and the human eye with a marked presence of spherical aberration (SA) and a natural apodization produced by the Stiles-Crawford effect. Results show that apodization only produces a refraction change of the plane that maximized the Strehl Ratio for large values of negative SA.
Hyperspectral image denoising using the robust low-rank tensor recovery
Yong Ma, Li chang, Huang Jun, Mei Xiaoguang, and Jiayi Ma
Doc ID: 238296 Received 16 Apr 2015; Accepted 02 Jul 2015; Posted 02 Jul 2015 View: PDF
Abstract: Denoising is an important preprocessing step to further analyze the hyperspectral image (HSI), and many denoising methods have been used for the denoising of the HSI data cube. However, the traditional denoising methods are sensitive to outliers and non-Gaussian noise. In this paper, by utilizing the underlying low-rank tensor property of the clean HSI data and the sparsity property of the outliers and non-Gaussian noise, we propose a new model based on the robust low-rank tensor recovery (RLRTR), which can simultaneously remove the outliers and dierent types of noise: Gaussian noise, impulse noise, stripes, and so on. The proposed model can be solved by the alternating direction augmented Lagrangian (ADAL) method, and experiments on real hyperspectral images demonstrate that the proposed method is ecient for HSI denoising.
Effect of the focus shaping generated from different double-mode cylindrical vector beams
Feng Song, Wenjing Cui, Guiyang Chen, Dandan Ju, and Feifei Song
Doc ID: 236547 Received 16 Apr 2015; Accepted 30 Jun 2015; Posted 02 Jul 2015 View: PDF
Abstract: We investigate three-dimensional focus shaping generated from double-mode cylindrical vector beams with the Gaussian and Bessel- Gaussian pupil apodization functions by choosing the suitable polarization states of beams. Further, we compare them with that generated from the Laguerre-Gaussian pupil apodization function in the same situation. We find that the focus shaping generated from the Gaussian beam has the smallest zero intensity spot size. However, the situation of the Bessel-Gaussian beam not only possesses stability which makes it suitable when applied in optical trapping, but also shows the best uniformity, which indicates its excellent performance in super-resolution fluorescence microscopy.
Rigorous solution for Gamo entropy under spatially partial coherent illumination
Doc ID: 238261 Received 20 Apr 2015; Accepted 22 Jun 2015; Posted 22 Jun 2015 View: PDF
Abstract: We present a calculation methodology for obtaining the rigorous solution of the Gamo entropy, which is defined by the intensity matrix proposed by Gamo [H. Gamo, J. Opt. Soc. Am. 47, 976 (1957)]. The matrix, which consists of numerous image amplitudes at all the sampling points of the entire imaging plane, is generally infinite-dimensional. It is essential that the computational difficulties arising due to the infinite-dimensionality are avoided by introducing the inner products of two image amplitudes. The integral in continuous space plays the role of a buffer against the infinite-dimensionality. The validity of the approach is confirmed by comparing our analytical solution and previous numerical simulations.
General Lossless Planar Coupler Design Algorithms
Doc ID: 240181 Received 01 May 2015; Accepted 21 Jun 2015; Posted 22 Jun 2015 View: PDF
Abstract: This paper reviews and extends two classes of algorithms for the design of planar couplers with any unitary transfer matrix as design goals. Such couplers find use in optical sensing for fading-free interferometry, coherent optical network demodulation and also for quantum state preparation in quantum optical experiments and technology. The two classes are (1) “atomic coupler algorithms” decomposing a unitary transfer matrix into a planar network of 2 2 couplers, and (2) “Lie-theoretic algorithms” concatenating unit cell devices with variable phase delay sets that form canonical co-ordinates for neighborhoods in the Lie group U(N), so that the concatenations realize any transfer matrix in U(N). As well as review, this paper gives (1) a Lie theoretic proof existence proof showing that both classes of algorithms work and (2) direct proofs of the efficacy of the“atomic coupler” algorithms. The Lie theoretic proof strengthens former results. 5 5 couplers designed by both methods are compared by Monte-Carlo analysis, which would seem to imply atomic rather than Lie theoretic methods yield designs more resilient to manufacturing imperfections.
Random errors for the measurement of central positions in white-light interferometry with the least-squares method
Doc ID: 240092 Received 01 May 2015; Accepted 21 Jun 2015; Posted 02 Jul 2015 View: PDF
Abstract: The paper analyses the effect of random noise on the measurement of central positions of white-light correlograms with the least-squares method. Measurements of two types of the central positions have been investigated, which are the central position of the envelope (CPE) and the central position of the central fringe (CPCF). Two types of random noise are considered, which are intensity noise and position noise. Analytic Expressions for random error due to intensity noise (REIN) and random error due to position noise (REPN) are derived. The theoretical results are compared with the random errors estimated from computer simulations. Random errors of CPE measurement are compared with those of CPCF measurement. Relationships are investigated between the random errors and the wavelength of the light source. The REPN of CPCF measurement has been found to be independent of the wavelength of the light source and the amplitude of the central fringe.
Point-by-point near-field optical energy deposition around plasmonic nanospheres in absorbing media
Richard Harrison and Adela Ben-Yakar
Doc ID: 240275 Received 06 May 2015; Accepted 20 Jun 2015; Posted 22 Jun 2015 View: PDF
Abstract: Here we investigate the effects of absorbing media on plasmon-enhanced near-field optical energy deposition. We find that increasing absorption by the medium results in increased particle scattering at the expense of particle absorption, and that much of this increased particle scattering is absorbed by the medium close to the particle surface. We present an analytical method for evaluating the spatial distribution of near-field enhanced absorption surrounding plasmonic metal nanospheres in absorbing media using a new point-by-point method. We propose criteria to define relevant near-field boundaries and calculate the properties of the local absorption enhancement, which redistributes absorption to the near-field and decays asymptotically as a function of distance from the particle to background levels. Using this method, we performed a large scale parametric study to understand the effect of particle size and wavelength on the near-field absorption for gold nanoparticles in aqueous media and silicon, and identifying conditions that are relevant to enhanced local infrared absorption in silicon. The presented approach provides insight into the local energy transfer around plasmonic nanoparticles for predicting near-field effects for advanced concepts in optical sensing, thin-film solar cells, nonlinear imaging, and photochemical applications.
The Lycurgus Cup: inverse problem using photographs for characterization of matter
Doc ID: 241311 Received 19 May 2015; Accepted 20 Jun 2015; Posted 24 Jun 2015 View: PDF
Abstract: Photographs of the Lycurgus cup with a source light inside and outside exhibit purple and green colors respectively (dichroism). A model relying the scattering of light to colors in photographs is proposed and used within an inverse problem algorithm, in order to deduce radius and composition of metallic particles, and refractive index of the surrounding glass medium. The inverse problem algorithm is based on an hybridization of the particle swarm optimization and of the simulated annealing methods. The results are compared to experimental measurements on a small sample of glass. The linear laws that are deduced from sets of possible parameters producing the same color in photographs, help simplify the understanding of phenomena. The proportion of silver to gold in nanoparticles is found in agreement, but a large proportion of copper is also found. The retrieved refractive index of the surrounding glass is close to 2.
Detection of chromatic and luminance distortions in natural scenes
Ben Jennings, Frederick Kingdom, Samantha Menzies, and Karen Wang
Doc ID: 236440 Received 18 Mar 2015; Accepted 16 Jun 2015; Posted 17 Jun 2015 View: PDF
Abstract: A number of previous studies have measured visual thresholds for detecting spatial distortions applied to images of natural scenes. One of these measured sensitivity to sinusoidal spatial modulations of image scale (Bex, 2010). Here we consider the relative contribution of the chromatic and luminance layers of natural-scene images to sinusoidal scale distortion. We first report that when the distortion was applied to both luminance and chromatic layers, sensitivity did not depend on whether the undistorted comparison image was of the same or of a different scene. Next we report the effects of individually distorting one or other layer. When only the luminance layer was distorted, performance was the same irrespective of whether the chromatic layer was present, absent or phase scrambled, revealing that the chromatic layer in whatever form did not affect sensitivity. However when the chromatic layer was distorted, sensitivity was higher when the luminance layer was intact compared to when absent or phase-scrambled. Moreover, even when the chromatic layer was visibly distorted, it appeared to contribute little to the sense of distortion. We conclude (a) that observers have an in-built sense of how a normal image of a natural scene should appear, and (b) that both the appearance and detection of distortion is mediated predominantly by the luminance as opposed to chromatic layer.
Exceptional polarization structures near the C-lines in diffracted near fields
Yu Renlong, Yu Xin, Qi Zhao, Yanming Shao, and yanru chen
Doc ID: 237447 Received 03 Apr 2015; Accepted 15 Jun 2015; Posted 15 Jun 2015 View: PDF
Abstract: We study the polarization structures in the vicinity of C-lines in the near fields diffracted from a pair of small holes. We find when the incident light is circularly polarized, both the true C-lines and the structures near them are controlled only by the longitudinal component. Furthermore, we find that all the existing singular lines of circular polarization have winding number ±1 , very different than the usual numbers ±1 2 , and the structure of major axes of the polarization ellipses surrounding these lines are shown to form structures different than the Möbius strip type. All these features prove to be stable upon small changes of shapes or positions of the apertures. However C-lines with unit winding number rupture into two C-lines of half winding number when the incident light degenerates into elliptically polarized light.
Design of guided-mode resonance mirrors for short laser cavities
Shogo Ura, Robert Magnusson, and Tomohiro Kondo
Doc ID: 239941 Received 04 May 2015; Accepted 12 Jun 2015; Posted 15 Jun 2015 View: PDF
Abstract: A guided-mode resonance mirror (GMRM) consists of a waveguide grating integrated on an optical buffer layer on a high reflection substrate. An incident free-space wave at the resonance wavelength is once coupled by the grating to a guided mode and coupled again by the same grating back to free space. The reflection characteristics of a GMRM are numerically calculated and theoretically analyzed. It is predicted that notch filtering or flat reflection spectra are obtained depending on the optical buffer layer thickness. Design of short cavities using a GMRM is discussed for potential application in surface-mount packaging of diode lasers onto a photonic circuit board.
An empirical model for matching spectrophotometric reflectance of yarn windings and multispectral imaging reflectance of single strands of yarns
Lin Luo, Hui-Liang Shen, Si-Jie Shao, and John Xin
Doc ID: 232029 Received 07 Jan 2015; Accepted 12 Jun 2015; Posted 15 Jun 2015 View: PDF
Abstract: The state-of-the-art multispectral imaging system can directly acquire the reflectance of a single strand of yarn that is impossible for traditional spectrophotometers. Instead, the spectrophotometric reflectance of a yarn winding, which is constituted by yarns winded on a background card, is regarded as the yarn reflectance in textile. While multispectral imaging systems and spectrophotometers can be separately used to acquire the reflectance of a single strand of yarn and corresponding yarn winding, the quantitative relationship between them is not yet known. In this paper, the relationship is established based on models which describe the spectral response of a spectrophotometer to a yarn winding and that of a multispectral imaging system to a single strand of yarn. The reflectance matching function from a single strand of yarn to corresponding yarn winding is derived to be a second degree polynomial function, which coefficients are the solutions of a constrained nonlinear optimization problem. Experiments on 100 pairs of samples show that the proposed approach can reduce the color difference between yarn windings and single strands of yarns from 2.449 to 1.082 CIEDE2000 units. The coefficients of optimal reflection matching function imply that the reflectance of a yarn winding measured by a spectrophotometer consists of not only the intrinsic reflectance of yarn but also the non-ignorable inter-reflection component between yarns.
Rigorous coupled wave analysis of acousto-optics with relativistic considerations
Guoqiang Xia, Weijian Zheng, Zhenggang Lei, and Ruolan Zhang
Doc ID: 235514 Received 25 Mar 2015; Accepted 11 Jun 2015; Posted 22 Jun 2015 View: PDF
Abstract: A relativistic analysis of acousto-optics is presented, and a rigorous coupled wave analysis is generalized for the diffraction of the acousto-optical effect. An acoustic wave generates a grating with temporally and spatially modulated permittivity, hindering direct applications of the rigorous coupled wave analysis for the acousto-optical effect. In a reference frame which moves with the acoustic wave, the grating is static and the medium moves and the coupled wave equations for the static grating may be derived. Floquet’s theorem is then applied to cast these equations into an eigen-problem. Using a Lorentz transformation, the electromagnetic fields in the grating region are transformed to the lab frame where the medium is at rest, and relativistic Doppler frequency shifts are introduced into various diffraction orders. In the lab frame, the boundary conditions are considered and the diffraction efficiencies of various orders are determined. This method is rigorous and general, and the plane waves in the resulting expansion satisfy the dispersion relation of the medium and are propagation modes. Properties of various Bragg diffractions are results, rather than preconditions, of this method. Simulations of an acousto-optical tunable filter made by paratellurite, TeO2, are given as examples.
Quantitative assessment of the impact of blood pulsation on images of the pupil in infrared light
Robert Koprowski, Henryk Kasprzak, Zygmunt Wróbel, Sławomir Wilczyński, and Marta Szmigiel
Doc ID: 225836 Received 29 Oct 2014; Accepted 08 Jun 2015; Posted 09 Jun 2015 View: PDF
Abstract: Pulsation in the blood vessels of the eye has a big impact on the dynamics of the entire eyeball and its individual elements. Blood pulsation in the retina can be recorded by the pupil whose size is also subject to dynamic changes. The study involved synchronous measurements of the pupil size, using a high speed camera, and blood pulsation, using a pulse oximeter placed on the ear lobe. In addition, there were no metrologically significant differences in the phase shift between the average brightness of the individual pupil quadrants. Blood pulsation in other ocular tissues can affect the dynamics of the optical properties of the eye. As demonstrated in this paper, it affects the pupil behaviour and its parameters to a considerable extent.
Electromagnetic inhomogeneous waves at planar boundaries
Nicola Tedeschi and Fabrizio Frezza
Doc ID: 236794 Received 25 Mar 2015; Accepted 05 Jun 2015; Posted 10 Jun 2015 View: PDF
Abstract: In this review paper, we summarize the fundamental properties of the inhomogeneous waves at the planar interface between two media. We point out the main differences between the wave types: the lateral wave, the surface wave, and the leaky wave. We analyze each kind of inhomogeneous wave, giving a quasi-optical description and explaining the physical origin of some of their properties.
Origins of Radiative Transport Theory: Diagrammatic and Multiscale Approaches
John Schotland and Alexandre Caze
Doc ID: 232297 Received 16 Jan 2015; Accepted 14 Mar 2015; Posted 17 Mar 2015 View: PDF
Abstract: The radiative transport equation (RTE) is widely used to describe the propagation of multiply- scattered light in disordered media. In this tutorial, we present two derivations of the RTE for scalar wave fields. The first derivation is based on diagrammatic perturbation theory, while the second stems from an asymptotic multiscale expansion. Although the two approaches are quite distinct mathematically, some common ground can be found and is discussed.
(CV) Independence and interaction of luminance and chromatic contributions to spatial hyperacuity performance
Bonnie Cooper and Barry Lee
Doc ID: 198653 Received 30 Sep 2013; Accepted 02 Feb 2014; Posted 03 Feb 2014 View: PDF
Abstract: Here we test interactions of luminance and chromatic input to spatial hyperacuity mechanisms. First, we tested alignment with matching or mismatching (contrast polarity or modality) grating pairs that were adjusted to detection threshold. Thresholds with mismatched pairs were significantly elevated. Second, we determined alignment acuity as a function of luminance or chromatic contrast alone or in the presence of contrast pedestals. For in-phase pedestal conditions, performance followed the envelope of the more sensitive mechanism. However, polarity reversals revealed an asymmetric effect for luminance and chromatic conditions. This suggests that luminance can overrule chromatic mechanisms in hyperacuity; we interpret these findings in the context of spatial mechanisms.