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Journal of the Optical Society of America A

Journal of the Optical Society of America A

| OPTICS, IMAGE SCIENCE, AND VISION

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Early Posting

Accepted papers to appear in an upcoming issue

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December


High quality computational ghost imaging using multi-fluorescent screen

  • Sohrab Ahmadi Kandjani, Hossein Ghanbari-Ghalehjoughi, and Mansour Eslami
  • received 10/06/2014; accepted 12/17/2014; posted 12/17/2014; Doc. ID 221509
  • [full text: PDF (1413) KB)]
  • Abstract: An alternative scheme for improvement of computational ghost imaging features is proposed based on 3-color fluorescent screen. While monochrome fluorescent screen does not enhance the quality of ghost images in comparison with ordinary ghost imaging technique, employment of a multi-fluorescent screen can be very effective. It is shown that the visibility, SNR and CNR of the resultant ghost images are improved when multi-fluorescent screen is used. In particular, the results prove 65, 36 and 95 percent of improvement for visibility, SNR and CNR over 2000 shots, respectively. Also shown is the possibility of reconstructing ghost images over reduced number of shots (as small as 25) by increasing the number of colors on the screen, whereas ordinary ghost imaging is not possible with such small number of shots. The results from simulations are checked with conducted experiments and a good agreement between them is observed.

Keywords (OCIS):

  • (030.0030) Coherence and statistical optics : Coherence and statistical optics
  • (110.1650) Imaging systems : Coherence imaging
  • (110.2990) Imaging systems : Image formation theory
  • (110.1758) Imaging systems : Computational imaging

An intelligent speckle reducing anisotropic diffusion algorithm for automated 3-D ultrasound images

  • Yuanyuan Wang, Jun Wu, Jinhua Yu, Xinling Shi, Junhua Zhang, Yue Chen, and Yun Pang
  • received 10/15/2014; accepted 12/16/2014; posted 12/16/2014; Doc. ID 224992
  • [full text: PDF (4252) KB)]
  • Abstract: A novel 3-D filtering method is presented for speckle reduction and detail preservation in automated 3-D ultrasound images. First, texture features of an image are analyzed by using the improved quadtree (QT) decomposition. Then, the optimal homogeneous and the obvious heterogeneous regions are selected from QT decomposition results. Finally, diffusion parameters and diffusion process are automatically decided based on the properties of these two selected regions. Since the computing time needed for 2-D speckle reduction is very short. The waiting time of 2-D filtering is acceptable. However, the computing time required for 3-D speckle reduction is often hundreds of times longer than 2-D speckle reduction. Due to that this new filter can adaptively adjust the time step of iteration, the computation time is reduced effectively. Both synthetic and real 3-D ultrasound images are used to evaluate the proposed filter. It is shown that this filter is superior to other methods in both practicality and efficiency.

Keywords (OCIS):

  • (030.4280) Coherence and statistical optics : Noise in imaging systems
  • (030.6140) Coherence and statistical optics : Speckle
  • (100.2980) Image processing : Image enhancement
  • (100.6890) Image processing : Three-dimensional image processing
  • (110.7170) Imaging systems : Ultrasound

Diffraction model of peristrophic multiplexing with spherical reference wave

  • Shuhei Yoshida, Yosuke Takahata, Shuma Horiuchi, and Manabu Yamamoto
  • received 09/11/2014; accepted 12/12/2014; posted 12/15/2014; Doc. ID 222829
  • [full text: PDF (524) KB)]
  • Abstract: Multiplexing recording is a primary contributor for determining the recording density in holographic data storage (HDS). Therefore, many different kinds of recording methods have been proposed. Among them, the method that utilizes spherical waves as a reference wave is characterized by its ability to enable multiplexing recording only by moving (shifting or rotating) the recording medium. In the research, we proposed a theoretically diffraction model of peristrophic multiplexing with spherical reference wave, and evaluate the diffraction efficiency; this multiplexing recording method has incorporated spherical reference waves in rotation of the media. Additionally, we verify the effectiveness of the model by comparing it with experimental results.

Keywords (OCIS):

  • (050.1950) Diffraction and gratings : Diffraction gratings
  • (090.7330) Holography : Volume gratings
  • (210.2860) Optical data storage : Holographic and volume memories

Differential Mueller matrix of a depolarizing homogeneous medium and its relation to the Mueller matrix logarithm

  • Razvigor Ossikovski and Antonello De Martino
  • received 10/13/2014; accepted 12/12/2014; posted 12/15/2014; Doc. ID 224810
  • [full text: PDF (432) KB)]
  • Abstract: The different z-dependence and non-commutativity of the two components of the differential Mueller matrix of a homogeneous depolarizing medium prevent from its formal identification with the Mueller matrix logarithm. By using a classic linear differential equation expansion, we advance a procedure for the extraction of the elementary polarization properties, in terms of mean values and variances - covariances, from the Mueller matrix logarithm. The approximate solution, based on the immediate identification of the differential matrix with the matrix logarithm, turns out to remain satisfactory up to relatively high depolarization levels. Physically interpreted experimental examples from the literature illustrate the formal developments.

Keywords (OCIS):

  • (260.0260) Physical optics : Physical optics
  • (260.2130) Physical optics : Ellipsometry and polarimetry
  • (260.5430) Physical optics : Polarization
  • (290.5855) Scattering : Scattering, polarization

Electromagnetic scattering by two concentric spheres buried in a stratied material

  • fabio mangini, Fabrizio Frezza, and Nicola Tedeschi
  • received 07/23/2014; accepted 12/11/2014; posted 12/18/2014; Doc. ID 217376
  • [full text: PDF (703) KB)]
  • Abstract: In this paper a rigorous method to analyze the electromagnetic scattering of an elliptically-polarized plane wave by two concentric spheres buried in a dielectric stratified medium, is presented. The interaction of the electromagnetic radiation with the stratified material is taken into account by means of the transfer matrix approach, in this way we can consider the stratified medium as an effective single interface. All the electromagnetic fields are expanded in series of spherical vector harmonics. The transmitted field through the stratified medium is obtained by means of the effective transmission coefficient. This field is scattered by the two concentric spheres and the scattered field interacts again with the stratified material. The scattered-reflected and scattered-transmitted fields by the layered medium are computed by exploiting the plane-wave spectrum of the scattered field, considering the reflection and transmission of each elementary plane wave by the effective interface. The boundary conditions imposition on the spheres' surfaces leads to a linear system that returns the unknown coefficients of the problem. A numerical code has been implemented to compute the field all-over the space. In order to compute the scattered fields, a truncation criterion has been proposed for the numerical evaluation of the series. Finally, to validate the presented method, comparisons between the results of the proposed code and those results of simulations with a software based on the Finite Element Method, have been implemented, showing very good agreement.

Keywords (OCIS):

  • (290.4020) Scattering : Mie theory
  • (290.5850) Scattering : Scattering, particles
  • (290.5825) Scattering : Scattering theory

Frequency correlations in reflection from random media

  • Thomas Wellens and Angelika Knothe
  • received 08/11/2014; accepted 12/09/2014; posted 12/16/2014; Doc. ID 220688
  • [full text: PDF (1833) KB)]
  • Abstract: We present a theoretical study of frequency correlations of light backscattered from a random scattering medium. This statistical quantity provides insight into the dynamics of multiple scattering processes accessible both, in theoretical and experimental investigations. For frequency correlations between field amplitudes, we derive a simple expression in terms of the path length distribution of the underlying backscattering processes. In a second step, we apply this relation to describe frequency correlations between intensities in the regime of weak disorder. Since, with increasing disorder strength, an unexplained breakdown of the angular structure of the frequency correlation function has recently been reported in experimental studies, we explore extensions of our model to the regime of stronger disorder. In particular, we show that closed scattering trajectories tend to suppress the angular dependence of the frequency correlation function.

Keywords (OCIS):

  • (030.5620) Coherence and statistical optics : Radiative transfer
  • (030.6140) Coherence and statistical optics : Speckle
  • (290.1350) Scattering : Backscattering
  • (290.4210) Scattering : Multiple scattering

Analysis of optical vortices with suppressed sidelobes using modified Bessel-like function and trapezoid annulus modulation structures

  • Zhongchao Wei, Jian Guo, Yuebo Liu, and Aili Huang
  • received 07/16/2014; accepted 12/09/2014; posted 12/09/2014; Doc. ID 216942
  • [full text: PDF (1476) KB)]
  • Abstract: Two amplitude modulation methods including modified Bessel-like function modulation structure and trapezoid annulus structure for suppressing sidelobes of optical vortices are studied. In the former approach, we propose that the order of the Bessel-like function can be an additional parameter to modulate diffraction patterns of optical vortices motivated by the idea of conventional annulus structures. Funthermore, new Bessel-like modulation functions are introduced to solve the problem of low diffraction efficiency of the original one. Trapezoid annulus structure is proposed as a compromise structure between the modified Bessel-like modulation structure and the conventional annulus one and owns advantages of both. It is demonstrated that these 2 approaches can achieve high quality optical vortices with suppressed sidelobes effectively and the relative structures behave as more flexible and applicable structures for producing optical vortices with large coverage of topological charges, which suggest great potential in simplifying the structure designing procedure. These reliable and generalized structures for generating high quality optical vortices will help to promote the development of future optical communication and optical manipulation significantly.

Keywords (OCIS):

  • (050.1970) Diffraction and gratings : Diffractive optics
  • (140.3300) Lasers and laser optics : Laser beam shaping
  • (050.4865) Diffraction and gratings : Optical vortices

A portable monocular light pen vision measurement system

  • Weimin Li and Yan Li
  • received 07/11/2014; accepted 12/08/2014; posted 12/09/2014; Doc. ID 216799
  • [full text: PDF (1129) KB)]
  • Abstract: This paper introduces a portable monocular vision measurement system which is suitable for measuring complex object surfaces or hidden features. The system mainly consists of a light pen, a camera, and a portable computer. Firstly, without any control point, a camera calibration method based on the bundle adjustment is developed. This method can also be applied to calculate the positions of the feature points on the light pen; secondly, we calibrate the probe tip center since the position of the replaceable stylus is uncertain; lastly, by taking images of the light pen when the stylus contacts the object’s surface, we get the measured point’s position. This measuring system is portable, efficient and high-precision. Experiments show that in a 100mm×200mm field, the position errors of 66 points are less than 30μm.

Keywords (OCIS):

  • (120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
  • (150.6910) Machine vision : Three-dimensional sensing
  • (330.4150) Vision, color, and visual optics : Motion detection
  • (330.7325) Vision, color, and visual optics : Visual optics, metrology

Creation of a 50,000λ long needle-like field with 0.36λ width: comment

  • Sabino Chavez-Cerda and Jixiong Pu
  • received 09/15/2014; accepted 12/08/2014; posted 12/09/2014; Doc. ID 223032
  • [full text: PDF (563) KB)]
  • Abstract: In a recent paper, a method for the generation of a long, narrow needle of light was proposed [J. Opt. Soc. Am. A 31, 500 (2014)]. The authors missed some fundamental aspects of the mathematical physics of cylindrical electromagnetic waves described by Bessel functions that are essential to obtain the desired result. Also, their solution of the wave field lacks the component of longitudinal energy flow that is needed for most of the applications they suggest. We show that a minor modification solves this absence with practically negligible increase of the needle width.

Keywords (OCIS):

  • (000.3860) General : Mathematical methods in physics
  • (030.1670) Coherence and statistical optics : Coherent optical effects
  • (260.1960) Physical optics : Diffraction theory
  • (260.2110) Physical optics : Electromagnetic optics
  • (070.3185) Fourier optics and signal processing : Invariant optical fields
  • (070.7345) Fourier optics and signal processing : Wave propagation

Effective and Efficient Subjective Testing of Texture Similarity Metrics

  • Thrasyvoulos Pappas, Jana Zujovic, David Neuhoff, Rene van Egmond, and Huib de Ridder
  • received 09/05/2014; accepted 12/06/2014; posted 12/09/2014; Doc. ID 222487
  • [full text: PDF (3159) KB)]
  • Abstract: The development and testing of objective texture similarity metrics that agree with human judgments of texture similarity require, in general, extensive subjective tests. The effectiveness and efficiency of such tests depend on a careful analysis of the abilities of human perception and the application requirements. The focus of this paper is on defining performance requirements and testing procedures for objective texture similarity metrics. We identify three operating domains for evaluating the performance of a similarity metric: the ability to retrieve "identical" textures; the top of the similarity scale, where a monotonic relationship between metric values and subjective scores is desired; and the ability to distinguish between perceptually similar and dissimilar textures. Each domain has different performance goals and requires different testing procedures. For the third domain, we propose ViSiProG, a new Visual Similarity by Progressive Grouping procedure for conducting subjective experiments that organizes a texture database into clusters of visually similar images. The grouping is based on visual blending, and greatly simplifies labeling image pairs as similar or dissimilar. ViSiProG collects subjective data in an efficient and effective manner, so that a relatively large database of textures can be accommodated. Experimental results and comparisons with structural texture similarity metrics demonstrate both the effectiveness of the proposed subjective testing procedure and the performance of the metrics.

Keywords (OCIS):

  • (100.2000) Image processing : Digital image processing
  • (100.2960) Image processing : Image analysis
  • (330.4060) Vision, color, and visual optics : Vision modeling
  • (330.7310) Vision, color, and visual optics : Vision
  • (110.3925) Imaging systems : Metrics
  • (100.4995) Image processing : Pattern recognition, metrics

Relativistic kinematics formulation of the polarization effects of Jones-Mueller matrices

  • Ghislain Franssens
  • received 06/12/2014; accepted 12/04/2014; posted 12/04/2014; Doc. ID 213938
  • [full text: PDF (330) KB)]
  • Abstract: The polarization of a partially coherent, transverse electric, electromagnetic plane wave is commonly represented by a Stokes vector. The similarity between Stokes vectors and four-momentum vectors in Special Relativity is studied in depth. The set of Stokes vectors naturally possesses an Euclidean and a Lorentzian geometry. The latter is used to express the polarization altering properties of Jones-Mueller matrices in a simple and elegant way. In particular, it is shown that the action of a diattenuator on a Stokes vector can be understood in terms of the addition law for velocities from Special Relativity. An important simplification in the resulting mathematical expressions further arises if the degree of polarization of a Stokes vector is represented by a hyperbolic polarization angle. This then allows to demonstrate that the output hyperbolic polarization angle is related to a diattenuator hyperbolic polarization angle and the input hyperbolic polarization angle by the hyperbolic law of cosines holding in a hyperbolic triangle..

Keywords (OCIS):

  • (120.2130) Instrumentation, measurement, and metrology : Ellipsometry and polarimetry
  • (230.5440) Optical devices : Polarization-selective devices
  • (260.5430) Physical optics : Polarization
  • (290.5855) Scattering : Scattering, polarization

The curvilinear coordinate method as an initial value problem - Application to gratings

  • Richard Dusseaux, Cihui Pan, Nahid Emad, and Mandiaye Fall
  • received 07/29/2014; accepted 12/04/2014; posted 12/04/2014; Doc. ID 220058
  • [full text: PDF (542) KB)]
  • Abstract: We propose an approach of the C-method for the efficient calculation of the scattering matrix of a grating. We consider two horizontal planes above and below the grating and define a coordinate system such that the grating surface and both horizontal planes correspond to surface coordinates. Inside the area A delimited by the horizontal planes, the covariant formalism of Maxwell’s equations leads to an initial value problem that is solved for independent initial conditions satisfying the boundary conditions. Outside the area A, the fields are represented by Rayleigh expansions. The scattering matrix is obtained by using continuity relations between different components of fields on the horizontal planes.

Keywords (OCIS):

  • (050.1950) Diffraction and gratings : Diffraction gratings
  • (050.1960) Diffraction and gratings : Diffraction theory
  • (240.6680) Optics at surfaces : Surface plasmons
  • (050.5745) Diffraction and gratings : Resonance domain

November


Action Recognition by Discovering Distinctive Action Parts

  • Feifei Chen, Nong Sang, Xiaoqin Kuang, Haitao Gan, and ChangXin Gao
  • received 06/02/2014; accepted 11/30/2014; posted 12/01/2014; Doc. ID 213138
  • [full text: PDF (2379) KB)]
  • Abstract: Recent methods based on mid-level visual concepts have shown promising capability in human action recognition field. Automatically discovering semantic entities such as action parts remains challenging. In this paper, we present a method to automatically discover distinctive mid-level action parts from videos for recognition of human actions. We address this problem by learning and selecting a collection of discriminative and representative action part detectors directly from video data. We initially train a large collection of candidate Exemplar-LDA detectors from clusters obtained by clustering spatiotemporal patches in whitened space. To select a subset of efficient detectors from the vast candidates, we propose a novel Coverage Entropy Curves (CE Curves) to evaluate the capability of a detector to distinguish actions. The CE-Curves characterize the correlation between representative and discriminative power of detectors. In the experiments, we apply the mined part detectors as visual vocabulary to the task of action recognition on four public datasets, KTH, Olympic Sports, UCF50, and HMDB51. The experimental results demonstrate the effectiveness of the proposed method and show the state-of-the-art recognition performance.

Keywords (OCIS):

  • (100.5010) Image processing : Pattern recognition
  • (150.4620) Machine vision : Optical flow
  • (150.1135) Machine vision : Algorithms
  • (110.4155) Imaging systems : Multiframe image processing

A Novel Method for Pan-tilt Camera Calibration Using Single Control Point

  • Yunting Li, Jun Zhang, Wenwen Hu, and Jinwen Tian
  • received 06/18/2014; accepted 11/30/2014; posted 12/01/2014; Doc. ID 214200
  • [full text: PDF (884) KB)]
  • Abstract: Pan-tilt (PT) camera is widely used in video surveillance system due to its rotatable property and low cost. The rough output of PT camera may not satisfy the demand of practical applications, hence an accurate calibration method of PT camera is desired. However, high-precision camera calibration methods usually require sufficient control points not guaranteed in some practical case of PT camera. In this paper, we present a novel method to online calibrate rotation the angles of PT camera by using only one control point. This is achieved by assuming that the intrinsic parameters and position of the camera are known in advance. More specifically, we first build a non-linear PT camera model with respect to two parameters Pan and Tilt. We then convert the non-linear model into a linear model according to sine and cosine of Tilt, where each element in the augmented coefficient matrix is a function of the single variable Pan. A closed-form solution of Pan and Tilt can then be derived by solving a quadratic equation of tangent of Pan. Our calibration method is validated on various synthetic and real data. The quantitative results demonstrate that the proposed method outperform other state-of-the-art methods if the intrinsic parameters and position of the camera are known in advance.

Keywords (OCIS):

  • (040.1490) Detectors : Cameras
  • (150.0155) Machine vision : Machine vision optics
  • (150.1135) Machine vision : Algorithms
  • (150.1488) Machine vision : Calibration

Tailoring the Negative-Refractive Index Metamaterials Composed of Semiconductor-Metal-Semiconductor Gold Ring/Disk Cavity Heptamers to Support Strong Fano Resonances in the Visible Spectrum

  • Arash Ahmadivand and Nezih Pala
  • received 07/18/2014; accepted 11/28/2014; posted 12/01/2014; Doc. ID 217303
  • [full text: PDF (877) KB)]
  • Abstract: In this study, we investigated the plasmon response of a planar negative-index metamaterial composed of symmetric molecular orientations of Au ring/disk nanocavities in a heptamer cluster, numerically. Using the plasmon hybridization theory and considering the optical response of an individual nanocluster, we determined the accurate geometrical sizes for a ring/disk nanocavity heptamer. It is shown that proposed well-organized nanocluster can be tailored to support strong and sharp Fano resonances in the visible spectrum. Surrounding and filling the heptamer clusters by various metasurfaces with different chemical characteristics, and illuminating the structure with an incident light source, we proved that this configuration reflects low-losses and isotropic features, which includes a pronounced Fano dip in the visible spectrum. Technically, employing numerical methods and tuning the geometrical sizes of the structure, we tuned and induced the Fano dip in the visible range, while the dark and bright plasmon resonance extremes are blue-shifted to shorter wavelengths dramatically. Considering calculated transmission window, we quantified the effective refractive index for the structure, while the substance of the substrate material is varied. Using Si, GaP, and InP semiconductors as substrate materials, we calculated and compared corresponding figure of merit (FOM) for different regimes. The highest possible FOM is obtained for the GaP-Au-GaP negative-refractive index metamaterial composed of ring/disk nanocavity heptamers as 62.4 at λ~690nm (around the position of the Fano dip). Despite of the outstanding symmetric nature of the suggested heptamer array, we provided sharp Fano dips by appropriate tuning of the geometrical and chemical parameters. This study yields a method to employ ring/disk nanocavity heptamers as a negative-refractive index metamaterial in designing highly accurate LSPR sensing devices and biochemical sensors.

Keywords (OCIS):

  • (290.5850) Scattering : Scattering, particles
  • (160.3918) Materials : Metamaterials
  • (280.4788) Remote sensing and sensors : Optical sensing and sensors
  • (250.5403) Optoelectronics : Plasmonics

Generation of cylindrically symmetric modes and orbital-angular-momentum modes with tilted optical gratings inscribed in high-numerical-aperture fiber

  • Liang Fang, Hongzhi Jia, Hai Zhou, and Baiying Liu
  • received 09/10/2014; accepted 11/27/2014; posted 12/01/2014; Doc. ID 222913
  • [full text: PDF (667) KB)]
  • Abstract: Optical fiber with high numerical aperture (NA) can efficiently relieve the degeneracy of higher-order linearly polarized (LP) modes. The degeneracy relief is investigated in two types of high NA fibers, i.e., low-index cladding fiber and high-index-core fiber. Naked-core fiber, as with low-index cladding, can theoretically used to generate the orbital-angular-momentum mode (OAMM) HE21 and the cylindrically symmetric modes (CSMs) TM01 and TE01. High-index-core fiber incorporated with high-contrast-index structure can be used similarly to obtain OAMM HE31. Both the generation of CSMs and OAMMs required tilted optical gratings to couple the fundamental core mode HE11 into these modes. Tilt angle and modulation period of the grating fringes can be calculated simply and accurately with the method proposed in this article.

Keywords (OCIS):

  • (060.2310) Fiber optics and optical communications : Fiber optics
  • (060.4080) Fiber optics and optical communications : Modulation
  • (060.3735) Fiber optics and optical communications : Fiber Bragg gratings
  • (130.5440) Integrated optics : Polarization-selective devices

GENERAL EXPRESSIONS FOR THE REFRACTIVE INDICES OF ABSORBING BIAXIAL MEDIA AS A FUNCTION OF THE ANGLE OF INCIDENCE

  • Jose Manuel Dineiro, Coro Alberdi, Carlos Saenz, and Begoña Hernández
  • received 09/18/2014; accepted 11/26/2014; posted 12/04/2014; Doc. ID 223389
  • [full text: PDF (2931) KB)]
  • Abstract: In this work we obtain general expressions for the complex refractive indices of the refracted waves as a function of the angle of incidence in the case of an electromagnetic wave propagating in a transparent isotropic medium that reaches an interface with a biaxial absorbing medium. The biaxial absorbing medium is only required to have a diagonalizable complex dielectric tensor. Obtained expressions can be applied to any orientation of the principal axes and can be specialized for isotropic, uniaxial or biaxial, transparent or absorbing media. Using these expressions we have also obtained the surface of indices and the surface of absorption coefficients for an example of biaxial absorbing medium.

Keywords (OCIS):

  • (260.0260) Physical optics : Physical optics
  • (260.2110) Physical optics : Electromagnetic optics

The effect of rotational diffusion in an orientational potential well on the Point Spread Function of electric dipole emitters

  • Sjoerd Stallinga
  • received 10/14/2014; accepted 11/24/2014; posted 12/01/2014; Doc. ID 224972
  • [full text: PDF (555) KB)]
  • Abstract: A study is presented of the Point Spread Function (PSF) of electric dipole emitters that go through a series of absorption-emission cycles while the dipole orientation is changing due to rotational diffusion within the constraint of an orientational potential well. An analytical expression for the PSF is derived valid for arbitrary orientational potential wells in the limit of image acquisition times much larger than the rotational relaxation time. This framework is used to study the effects of the direction of incidence, polarization and degree of coherence of the illumination. In the limit of fast rotational diffusion on the scale of the fluorescence lifetime the illumination influences only the PSF height, not its shape. In the limit of slow rotational diffusion on the scale of the fluorescence lifetime there is a significant effect on the PSF shape as well, provided the illumination is (partially) coherent. For oblique incidence illumination asymmetries can arise in the PSF that give rise to position offsets in localization based on Gaussian spot fitting. These asymmetries persist in the limit of free diffusion in a zero orientational potential well.

Keywords (OCIS):

  • (100.6640) Image processing : Superresolution
  • (110.2990) Imaging systems : Image formation theory
  • (180.2520) Microscopy : Fluorescence microscopy

Preparing the Generalized Harvey-Shack rough surface scattering method for use with the Discrete Ordinates Method

  • Villads Egede Johansen
  • received 09/05/2014; accepted 11/19/2014; posted 11/20/2014; Doc. ID 221781
  • [full text: PDF (932) KB)]
  • Abstract: This paper shows how to implement the Generalized Harvey-Shack (GHS) method for isotropic rough surfaces discretized in a polar coordinate system and approximated using Fourier series. This is in particular relevant for the use of the GHS method as boundary condition for radiative transfer problems in slab geometries, where the Discrete Ordinates method can be applied to solve the problem. Furthermore, such an implementation is a more natural discretization of the problem than the traditional direction cosine space that has its strengths in analytical problems and intuitive understanding (mainly due to its translation invariance). A computer implementation of scattering from a Gaussian rough surface with Gaussian autocovariance written in Python is included at the end of this paper.

Keywords (OCIS):

  • (240.5770) Optics at surfaces : Roughness
  • (290.7050) Scattering : Turbid media
  • (290.1483) Scattering : BSDF, BRDF, and BTDF
  • (290.5835) Scattering : Scattering, Harvey
  • (010.5620) Atmospheric and oceanic optics : Radiative transfer

Generalized propagation of light through optical systems I: Mathematical basics

  • Manuel Tessmer and Herbert Gross
  • received 08/27/2014; accepted 11/11/2014; posted 11/14/2014; Doc. ID 221782
  • [full text: PDF (1341) KB)]
  • Abstract: The propagation of an input field through tilted and curved surfaces is presented and applied for a field tracing routine. This routine employs a ray tracing method for optimal coordinate customization, which is done due to the strong linear phase terms that arise because of tilted coordinates on the one hand and the possibility of an application of fast numerical routines on the other. Several methods are proposed how to optimize the field sampling during the propagation process, as for the astigmatic phase front problem and the curvature of the surface itself. Two solution methods are given to propagate from the curved surface through the homogeneous space to another two-dimensional sub-manifold. The approach is fully-vectorial, Maxwell-exact excluding only surface curvature terms for the Fresnel coefficients. A simple numerical propagation example is given.

Keywords (OCIS):

  • (000.3860) General : Mathematical methods in physics
  • (070.0070) Fourier optics and signal processing : Fourier optics and signal processing
  • (220.2560) Optical design and fabrication : Propagating methods
  • (070.7345) Fourier optics and signal processing : Wave propagation

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