Showing papers on "Physical optics published in 2012"
01 Jan 2012
TL;DR: In this paper, the authors investigated the loss caused by multiple humans blocking millimeter wave frequencies by modeling human blockers as absorbing screens of infinite height with two knife-edges, and they used a physical optics approach to compute the diffraction around the absorbing screens.
Abstract: In this paper, we investigate the loss caused by multiple humans blocking millimeter wave frequencies. We model human blockers as absorbing screens of infinite height with two knife-edges. We take a physical optics approach to computing the diffraction around the absorbing screens. This approach differs to the geometric optics approach described in much of the literature. The blocking model is validated by measuring the gain from multiple-human blocking configurations on an indoor link. The blocking gains predicted using Piazzi’s numerical integration method (a physical optics method) agree well with measurements taken from approximately 2.7 dB to -50 dB. Thereofre, this model is suitable for real human blockers. The mean prediction error for the method is approximately -1.2 dB, and the standard deviation is approximately 5 dB.
95 citations
TL;DR: Detailed analysis of the impact and the interplay of various diffraction orders to the formation of Talbot images provides new insights into the fundamental properties of gratings that often find use in applications such as, e.g., lithography, sensing, and imaging.
Abstract: By means of experiment and simulation, we achieve unprecedented insights into the formation of Talbot images to be observed in transmission for light diffracted at wavelength-scale amplitude gratings. Emphasis is put on disclosing the impact and the interplay of various diffraction orders to the formation of Talbot images. They can be manipulated by selective filtering in the Fourier plane. Experiments are performed with a high-resolution interference microscope that measures the amplitude and phase of fields in real-space. Simulations have been performed using rigorous diffraction theory. Specific phase features, such as singularities found in the Talbot images, are discussed. This detailed analysis helps to understand the response of fine gratings. It provides moreover new insights into the fundamental properties of gratings that often find use in applications such as, e.g., lithography, sensing, and imaging.
72 citations
TL;DR: The Rayleigh-Sommerfeld back-propagation method is a fast and highly flexible volume reconstruction scheme for digital holographic microscopy as discussed by the authors, which can be used to discriminate between objects lying on either side of the holographic image plane.
Abstract: The Rayleigh-Sommerfeld back-propagation method is a fast and highly flexible volume reconstruction scheme for digital holographic microscopy. We present a new method for 3D localization of weakly scattering objects using this technique. A well-known aspect of classical optics (the Gouy phase shift) can be used to discriminate between objects lying on either side of the holographic image plane. This results in an unambiguous, model-free measurement of the axial coordinate of microscopic samples, and is demonstrated both on an individual colloidal sphere, and on a more complex object — a layer of such particles in close contact.
56 citations
TL;DR: A novel method of simulating wave effects in graphics using ray-based renderers with a new function: the Wave BSDF (Bidirectional Scattering Distribution Function), which circumvent the need to explicitly keep track of the phase of the wave by using BSDFs that include positive as well as negative coefficients.
Abstract: We present a novel method of simulating wave effects in graphics using ray-based renderers with a new function: the Wave BSDF (Bidirectional Scattering Distribution Function). Reflections from neighboring surface patches represented by local BSDFs are mutually independent. However, in many surfaces with wavelength-scale microstructures, interference and diffraction requires a joint analysis of reflected wavefronts from neighboring patches. We demonstrate a simple method to compute the BSDF for the entire microstructure, which can be used independently for each patch. This allows us to use traditional ray-based rendering pipelines to synthesize wave effects. We exploit the Wigner Distribution Function (WDF) to create transmissive, reflective, and emissive BSDFs for various diffraction phenomena in a physically accurate way. In contrast to previous methods for computing interference, we circumvent the need to explicitly keep track of the phase of the wave by using BSDFs that include positive as well as negative coefficients. We describe and compare the theory in relation to well-understood concepts in rendering and demonstrate a straightforward implementation. In conjunction with standard raytracers, such as PBRT, we demonstrate wave effects for a range of scenarios such as multibounce diffraction materials, holograms, and reflection of high-frequency surfaces.
52 citations
TL;DR: In this article, an efficient implementation of the hybrid method of moments (MoM)-physical optics (PO) hybrid technique is presented to avoid the calculation of the PO contribution in matrix form for electrically large objects.
Abstract: The conventional hybrid method of moments (MoM)-physical optics (PO) technique provides a possible way to handle electrically large objects with affordable computer memory However, its efficiency is not very good because the evaluation of the PO contribution to the MoM impedance matrix is very time-consuming An efficient implementation of the iterative MoM-PO hybrid technique is presented in this paper to avoid the calculation of the PO contribution in matrix form For electrically large objects, the proposed efficient iterative MoM-PO (EI-MoM-PO) method can greatly reduce the computational time and maintain the same or better accuracy with the same number of unknowns compared with the conventional MoM-PO method Several examples of large-scale structures are analyzed by the EI-MoM-PO method, the conventional MoM-PO method, and the multilevel fast multipole algorithm The excellent efficiency and accuracy are achieved by the proposed EI-MoM-PO technique
51 citations
TL;DR: Using azimuthal polarization, it is shown that an amplitude-phase filter allows generation of a subdiffractive dark spot in a prescribed finite area.
Abstract: We compare generation of a dark spot using focusing of beams with azimuthal polarizion, radial polarization with a vortex, and a circular polarization with either a first or second order vortex. By optimization of the amplitude-phase pupil, it is ascertained that azimuthal polarization is the most suitable one to obtain the diffraction bounded dark spot per se whose scalar approximation limit has FWHM=0.29λ. Consequently, for dark spot generation, this polarization plays the role of the radial polarization in creation of the diffraction-limited bright spot. Using azimuthal polarization, it is shown that an amplitude-phase filter allows generation of a subdiffractive dark spot in a prescribed finite area.
47 citations
TL;DR: An analytical expression for the log-amplitude correlation function for plane wave propagation through anisotropic non-Kolmogorov turbulent atmosphere is derived and agrees well with wave optics simulation based on the more general Fresnel approximation and with numerical evaluations, for low-to-moderate strengths of turbulence.
Abstract: An analytical expression for the log-amplitude correlation function for plane wave propagation through anisotropic non-Kolmogorov turbulent atmosphere is derived. The closed-form analytic results are based on the Rytov approximation. These results agree well with wave optics simulation based on the more general Fresnel approximation as well as with numerical evaluations, for low-to-moderate strengths of turbulence. The new expression reduces correctly to the previously published analytic expressions for the cases of plane wave propagation through both nonisotropic Kolmogorov turbulence and isotropic non-Kolmogorov turbulence cases. These results are useful for understanding the potential impact of deviations from the standard isotropic Kolmogorov spectrum.
40 citations
TL;DR: In this paper, an analytic scattering model for 3D bistatic scattering from a dihedral using geometrical optics (GO) and physical optics (PO) is derived, and the resulting parametric scattering model is presented in terms of the vertical and horizontal co-polarization and cross polarization responses that correspond to the outputs of industry-standard numerical prediction codes.
Abstract: We derive an analytic scattering model for 3D bistatic scattering from a dihedral using geometrical optics (GO) and physical optics (PO). We use GO to trace ray reflections, and we evaluate the PO integral(s) for the field scattered by each plate of the dihedral. Multiple cases of reflection geometry are considered to account for effects of the dihedral plate size and antenna aspect angles. The complex-valued (amplitude and phase) scattering response is derived. The resulting parametric scattering model is presented in terms of the vertical and horizontal co-polarization and cross-polarization responses that correspond to the outputs of industry-standard numerical prediction codes. Comparing the derived model to available codes for method of moments (MoM), shooting and bouncing rays (SBR), and parametric models (PM), we demonstrate that the derived solution achieves the same accuracy as SBR, approximates MoM, is more accurate than PM, and does so in fast computation time comparable to a PM.
38 citations
TL;DR: A wave optics numerical analysis of the force and torque on a semicylindrical optical wing is presented and it is found that the dominant rotationally stable angle of attack at α≈-15° is relatively invariant to changes in radius and refractive index.
Abstract: A wave optics numerical analysis of the force and torque on a semicylindrical optical wing is presented. Comparisons with a recently reported ray optics analysis indicate good agreement when the radius is large compared with the wavelength of light, as expected. Surprisingly, we find that the dominant rotationally stable angle of attack at α≈−15° is relatively invariant to changes in radius and refractive index. However, the torsional stiffness at the equilibrium point is found to increase, approximately, as the cubic power of the radius. Quasi-resonant internal modes of light produce complex size-dependent variations of the angle and magnitude of the optical lift force.
36 citations
TL;DR: This paper analyzes the scattering properties of the satellite by employing the GPU-based combinational method of geometrical optics and physical optics together with the kd-tree technique, and finds that the improved method yields a superior performance at high frequency.
Abstract: In the radar cross section (RCS) prediction of complex target, the intensive computational burden occurs while calculating the multiple scattering effect. In order to overcome the large computing, we present the program executing on graphics processing units (GPUs). In this paper, we analyze the scattering properties of the satellite, on which the antennas are described as cubes and columns, by employing the GPU-based combinational method of geometrical optics (GO) and physical optics (PO) together with the kd-tree technique. Furthermore, due to this distinctive treatment, the improved method yields a superior performance at high frequency. Some examples will be displayed in the following text. The agreement of the results yielded in this paper with the experimental and other exact results demonstrates the accuracy and efficiency of this useful technique.
35 citations
TL;DR: In this paper, the performance of a multibeam laser system is evaluated for coherent and incoherent beam combination under tactical scenarios, assuming a multilaser source coupled with a conventional 0.32 m diameter, on-axis, beam director.
Abstract: The performance of a multibeam laser system is evaluated for coherent and incoherent beam combination under tactical scenarios. For direct comparison, identical aperture geometries are used for both, coherent or incoherent, combination methods. The analysis assumes a multilaser source coupled with a conventional 0.32 m diameter, on-axis, beam director. Parametric analysis includes variations over residual errors, beam quality, atmospheric effects, and scenario geometry. Analytical solutions from previous results are used to evaluate performance for the vacuum case, providing an upper bound on performance and a backdrop for organizing the multitude of effects as they are analyzed. Wave optics simulations are used for total system performance. Each laser in the array has a wavelength of 1.07 μm, 10 kW (25 kW) output power, and Gaussian exitance profile. Both tracking and full-aperture adaptive optics are modeled. Three tactical engagement geometries, air to surface, surface to air, and surface to surface, are evaluated for slant ranges from 2.5 to 10 km. Two near-median atmospheric profiles were selected based upon worldwide climatological data. The performance metric used is beam propagation efficiency for circular target diameters of 5 and 10 cm.
TL;DR: It is shown that point source approximation is acceptable in cases when the size of the light source is 5 (or more) times less than the distance to the inner surface of the optical element.
Abstract: We present the method for computation of highly effective total internal reflection (TIR) optics for LED-based illumination systems. The computation problem is reduced to the integration of several explicit independent first-order differential equations. Two designs of TIR optics are considered and compared: with flat and with aspherical upper surface. The dependence of nonuniformity of generated irradiance distribution on the size of the light source is studied for both designs numerically. It is shown that point source approximation is acceptable in cases when the size of the light source is 5 (or more) times less than the distance to the inner surface of the optical element.
TL;DR: In this article, the resonant-state expansion (RSE) is applied to planar, effectively one-dimensional optical systems, such as layered dielectric slabs and Bragg reflector microcavities.
Abstract: The resonant-state expansion (RSE), a rigorous perturbation theory of the Brillouin-Wigner type recently developed in electrodynamics[ E. A. Muljarov, W. Langbein and R. Zimmermann Europhys. Lett. 92 50010 (2010)], is applied to planar, effectively one-dimensional optical systems, such as layered dielectric slabs and Bragg reflector microcavities. It is demonstrated that the RSE converges with a power law in the basis size. Algorithms for error estimation and their reduction by extrapolation are presented and evaluated. Complex eigenfrequencies, electromagnetic fields, and the Green's function of a selection of optical systems are calculated, as well as the observable transmission spectra. In particular, we find that for a Bragg-mirror microcavity, which has sharp resonances in the spectrum, the transmission calculated using the RSE reproduces the result of the transfer- or scattering-matrix method.
Book•
02 Dec 2012
TL;DR: Nonlinear guided wave optics, GI Stegeman optical solitons, GP Agrawal optical phase conjugation, RW Boyd and G Grynberg ultrafast nonlinear optics, IA Walmsley and JD Kafka quantum statistics in nonlinear projections, J Mostowski and MG Raymar photorefractive adaptive neural networks, JH Hong and D Psaltis nonlinear optical effects in organic materials, PN Prasadnonlinear optics in quantum confined structures, C Flytzanis and J Hutter nonlinear laser spectroscopy - saturation resonances
Abstract: Nonlinear guided wave optics, GI Stegeman optical solitons, GP Agrawal optical phase conjugation, RW Boyd and G Grynberg ultrafast nonlinear optics, IA Walmsley and JD Kafka quantum statistics in nonlinear optics, J Mostowski and MG Raymar photorefractive adaptive neural networks, JH Hong and D Psaltis nonlinear optical effects in organic materials, PN Prasad nonlinear optics in quantum confined structures, C Flytzanis and J Hutter nonlinear laser spectroscopy - saturation resonances, VP Chebotayev temporal and spatial instabilities and nonlinear dynamics in lasers and optical bistability, NB Abraham
TL;DR: In this article, the authors present exact solutions of the wave equation involving an arbitrary wave form with a phase closely similar to the general astigmatic phase of paraxial wave optics, which are generalizations of the known Bateman-type wave solutions.
Abstract: We present exact solutions of the wave equation involving an arbitrary wave form with a phase closely similar to the general astigmatic phase of paraxial wave optics. Special choices of the wave form allow general astigmatic beamlike and pulselike waves with a Gaussian-type unrestricted localization in space and time. These solutions are generalizations of the known Bateman-type waves obtained from the connection existing between beamlike solutions of the paraxial parabolic equation and relatively undistorted wave solutions of the wave equation. As a technical tool, we present a full description of parametrizations of $2\ifmmode\times\else\texttimes\fi{}2$ symmetric matrices with positive imaginary part, which arise in the theory of Gaussian beams.
TL;DR: In this paper, a delaminating quadrature method was proposed to calculate the physical optics (PO) integrals over non-uniform rational B-spline (NURBS) surfaces.
Abstract: Physical optics (PO) is a widely used radar cross section (RCS) estimation approach for electrically large-scaled objects, and it is finally reduced to the calculation of highly oscillatory integrals. In this paper the PO integrals over non-uniform rational B-spline (NURBS) surfaces is proposed to be calculated with a delaminating quadrature method. The method has the merits of being very stable, accurate, and fast, and its computation cost does not increase with frequency. Moreover, in order to keep these good properties for PO integrals involving critical points (stationary phase point, resonant point), a scheme of integral-subdividing is proposed, and new approaches for locating the critical points are also presented. Numerical examples of flat surface, cylindrical surface, and spherical surface well show the advantages of the new method.
TL;DR: It is shown that the vector field decomposition method, namely, the Helmholtz Hodge decomposition, can also be applied to analyze scalar optical fields that are ubiquitously present in interference and diffraction optics.
Abstract: It is shown that the vector field decomposition method, namely, the Helmholtz Hodge decomposition, can also be applied to analyze scalar optical fields that are ubiquitously present in interference and diffraction optics. A phase gradient field that depicts the propagation and Poynting vector directions can hence be separated into solenoidal and irrotational components.
14 Dec 2012
TL;DR: In this paper, Lakshminarayanan and S.Rodriguez proposed the Decomposition Method to Solve Differential Equations (DME) for optical applications.
Abstract: Special Problems in Ray Optics Orbital Angular Momentum: A Ray Optical Interpretation, M. Padgett Wigner Distributions Moments for Beam Characterization, T. Alieva, A. Camara, and M.J. Bastiaans Dynamic Programming Applications in Optics, M.L. Calvo, J. Perez-Rios, and V. Lakshminarayanan Mathematical Formalism in Wave Optics Basis Expansions for Monochromatic Field Propagation in Free Space, M.A. Alonso and N.J. Moore Solutions of Paraxial Equations and Families of Gaussian Beams, E. Abramochkin, T. Alieva, and J.A. Rodrigo The Decomposition Method to Solve Differential Equations: Optical Applications, V. Lakshminarayanan and S. Nandy Plasmonics An Introduction to Mathematics of Transformational Plasmonics, M. Kadic, S. Guenneau, and S. Enoch Plasmonics: Computational Approach, M. Sukharev Applications of Group Theory in Optics Lorentz Group in Ray and Polarization Optics, S. Baskal and Y.S. Kim Paraxial Wave Equation: Lie Algebra-Based Approach, A. Torre Dihedral Polynomials, M. Viana Lie Algebra and Liouville Space Methods in Quantum Optics, M. Ban Quantum Optics Methods From Classical to Quantum Light and Vice Versa: Quantum Phase-Space Methods, A. Luis Coherence Functions in Classical and Quantum Optics, I. Ashraf Zahid and V. Lakshmianrayanan Quantum Memory Channels in Quantum Optics, T. Rybar, M. Zyman, and V. Buzek Computational Optics/Image Processing An Introduction to Super-Resolution Imaging, J.D. Simpkins and R.L. Stevenson The Differential Structure of Images, B.M. ter Haar Romeny Index
TL;DR: The comparison shows that the simple ray-tracing is applicable to calculate the total absorptance and the absorbed intensity of polarized beams in several capillary geometries but not in rectangular grooves.
Abstract: Ray-tracing is the commonly used technique to calculate the absorption of light in laser deep-penetration welding or drilling. Since new lasers with high brilliance enable small capillaries with high aspect ratios, diffraction might become important. To examine the applicability of the ray-tracing method, we studied the total absorptance and the absorbed intensity of polarized beams in several capillary geometries. The ray-tracing results are compared with more sophisticated simulations based on physical optics. The comparison shows that the simple ray-tracing is applicable to calculate the total absorptance in triangular grooves and in conical capillaries but not in rectangular grooves. To calculate the distribution of the absorbed intensity ray-tracing fails due to the neglected interference, diffraction, and the effects of beam propagation in the capillaries with sub-wavelength diameter. If diffraction is avoided e.g. with beams smaller than the entrance pupil of the capillary or with very shallow capillaries, the distribution of the absorbed intensity calculated by ray-tracing corresponds to the local average of the interference pattern found by physical optics.
TL;DR: The first observation (to the best knowledge) of a constant intensity, quasi-Bessel/nondiffracting beam in an absorbing medium generated by a novel optical element, "exicon," or exponential intensity axicon is reported.
Abstract: We report the first observation (to our best knowledge) of a constant intensity, quasi-Bessel/nondiffracting beam in an absorbing medium generated by a novel optical element, “exicon,” or exponential intensity axicon. Such absorption-compensated and diffraction-resistant beams can find applications in illumination, remote sensing, free-space communications, imaging in biological tissues, nonlinear optics, and other situations where absorption and diffraction hinder light propagation.
TL;DR: The introduction of a peakedness correction based upon the excess kurtosis of slopes is necessary to obtain consistent analysis across the microwave frequency range and the model yields accurate simulations for the omnidirectional near-nadir normalized radar cross section in different frequency bands.
Abstract: The simulation and interpretation of microwave sea radar return in the near-nadir region are still issues in view of the limitations of the geometrical optics approximation and the multiscale and non-Gaussian nature of the surface. We show that an unambiguous and fully consistent physical approach can be reached in the framework of the physical optics. The model is developed on the basis of various satellite and airborne C-, Ku-, and Ka-band measurements using different reference surface roughness spectra. As found, the introduction of a peakedness correction based upon the excess kurtosis of slopes is necessary to obtain consistent analysis across the microwave frequency range. The model yields accurate simulations for the omnidirectional near-nadir normalized radar cross section in different frequency bands, provided the spectrum satisfies some a priori constraints on the distribution of the total and filtered slopes.
TL;DR: In this article, the authors give a positive answer to the question of whether the two effects are common in nature and study both effects in the more general context of optical beam shifts.
Abstract: The law of reflection and Snell's law are among the tenets of geometrical optics. Corrections to these laws in wave optics are respectively known as the angular Goos-Hanchen shift and Fresnel filtering. In this paper we give a positive answer to the question of whether the two effects are common in nature and we study both effects in the more general context of optical beam shifts. We find that both effects are caused by the same principle, but have been defined differently. We identify and discuss the similarities and differences that arise from the different definitions.
TL;DR: This work divides generalized laws of refraction into two categories based on the fact that scalar wave optics allows only certain light-ray fields, and states that when applied to a planar cross section through any allowed light-rays field, the laws always result in a cross sectionthrough an allowedLight-ray field again.
Abstract: The recent demonstration of a metamaterial phase hologram so thin that it can be classified as an interface in the effective-medium approximation [Science 334, 333 (2011)] has dramatically increased interest in generalized laws of refraction. Based on the fact that scalar wave optics allows only certain light-ray fields, we divide generalized laws of refraction into two categories. When applied to a planar cross section through any allowed light-ray field, the laws in the first category always result in a cross section through an allowed light-ray field again, whereas the laws in the second category can result in a cross section through a forbidden light-ray field.
TL;DR: A first-order approximation is derived for the near-critical-angle scattering of a large spheroidal bubble illuminated by a plane wave propagating along the bubble axis of symmetry.
Abstract: A first-order approximation is derived for the near-critical-angle scattering of a large spheroidal bubble illuminated by a plane wave propagating along the bubble axis of symmetry. The intensity of the far-field scattering pattern is expressed as a function of the relative refractive index and the two radii of curvature of the spheroidal bubble at the critical impact point.
TL;DR: It is shown that metrological resolution in the detection of small phase shifts provides a suitable generalization of the degrees of coherence and polarization.
Abstract: We show that metrological resolution in the detection of small phase shifts provides a suitable generalization of the degrees of coherence and polarization. Resolution is estimated via Fisher information. Besides the standard two-beam Gaussian case, this approach provides also good results for multiple field components and nonGaussian statistics. This works equally well in quantum and classical optics.
TL;DR: In this article, a time-domain physical optics (PO) integral is formulated under the incidence of plane waves and observation in the far-field region, and the efficiency and accuracy of the closed-form expression in the time domain are demonstrated through a number of numerical examples.
Abstract: In the conventional time-domain physical optics (PO) method, the far fields scattered by a metallic plate S of arbitrary shape have been given by a surface integral. However, the numerical evaluation of such a surface integral is time-consuming, which becomes the crux of time-domain PO technique. In this letter, a time-domain PO integral is formulated under the incidence of plane waves and observation in the far-field region. Then, the surface integral over S is reduced to a line integral around the boundary of S . When S is a polygon, the line integral is further reduced to a closed-form expression, which is very similar to the well-known Gordon formula in the evaluation of PO integral in the frequency domain. When S is arbitrarily shaped, the integral evaluation is also efficient once the polygon mesh is given. The efficiency and accuracy of the closed-form expression in the time domain are demonstrated through a number of numerical examples.
TL;DR: In this article, the authors studied the scattering of electromagnetic spherical wave by a perfectly conducting circular disk by using the method of Kobayashi potential (abbreviated as KP method).
Abstract: The scattering of electromagnetic spherical wave by a perfectly conducting circular disk is studied by using the method of Kobayashi Potential (abbreviated as KP method). The formulation of the problem yields the dual integral equations (DIE). The spherical wave is produced by an arbitrarily oriented dipole. The unknowns are the induced surface current (or magnetic fleld) and the tangential components of the electric fleld on the disk. The solution for the surface current is expanded in terms of a set of functions which satisfy one of a pair (equations for the magnetic fleld) of Maxwell equations and the required edge condition on the surface of the disk. At this stage we have used the vector Hankel transform. Applying the projection solves the rest of the pair of equations. Thus the problem reduces to the matrix equations for the expansion coe-cients. The matrix elements are given in terms of the inflnite integrals with a single variable and these may be transformed into inflnite series that are convenient for numerical computation. The far fleld patterns of the scattered wave are computed and compared with those computed based on the physical optics approximation. The agreement between them is fairly good.
TL;DR: In this paper, the multilevel physical optics (MLPO) algorithm aiming at the comprehensive analysis of complex reflector antenna systems is presented, where the physical theory of diffraction (PTD) line integral along the rim of a reflector is combined with the physical optics surface integral within the multi-level algorithm.
Abstract: Recent developments of the multilevel physical optics (MLPO) algorithm aiming at the comprehensive analysis of complex reflector antenna systems are presented. The physical theory of diffraction (PTD) line integral along the rim of a reflector is combined with the physical optics (PO) surface integral within the multilevel algorithm. The multilevel scheme is also generalized to combine fields radiated by various components of different sizes, as encountered in complex antenna systems with multiple feeds and/or reflectors. Comparison with published results demonstrates the ability of the MLPO algorithm to cope accurately and efficiently with realistic reflector antenna problems.
Book•
01 Dec 2012
TL;DR: In this paper, the authors describe a single-dish Diffraction-limited imaging system for astronomy with diluted aperture interferometry, which is based on the Zernike representation of atmospheric Turbulence.
Abstract: Preface.- Principal Symbols.- List of Acronyms.- Introduction to Wave Optics.- Principles of Interference.- Applications of Interferometry.- Single-dish Diffraction-limited Imaging.- Basic Tools and Technical Challenges.- Discrete-element Interferometers.- Image Recovery.- Astronomy with Diluted Aperture Interferometry.- Appendix A: Transfer Function of an Optical System.- Appendix B: Fourier Optics.- Appendix C: Spatial Frequency Response.- Appendix D: Zernike Representation of Atmospheric Turbulence.- Appendix E: Celestial Coordinate System.- References.- Index.
TL;DR: In this article, a generalized network formulation using a spherical wave expansion is applied to the analysis of the perturbation induced at the input port of an antenna by nearby scatterers.
Abstract: A generalized network formulation using a spherical wave expansion is applied to the analysis of the perturbation induced at the input port of an antenna by nearby scatterers. The antenna is characterized by using the total scattering matrix; the scattering from the obstacles is studied through a physical optics approach, and the interactions are described in terms of radiated spherical waves. The resulting procedure is simple, has a moderate computational cost and can be directly interfaced with measurements. Results show a very good agreement with full-wave simulations.