scispace - formally typeset
Search or ask a question

Showing papers in "Journal of The Optical Society of America A-optics Image Science and Vision in 2011"


Journal ArticleDOI
TL;DR: It is demonstrated that diffraction patterns can be extrapolated beyond the aperture of the recording device, leading to superresolved images, improving the limit on the finest feature separation by more than a factor of 3.
Abstract: Coherent diffractive imaging of objects is made considerably more practicable by using ptychography, where a set of diffraction patterns replaces a single measurement and introduces a high degree of redundancy into the recorded data. Here we demonstrate that this redundancy allows diffraction patterns to be extrapolated beyond the aperture of the recording device, leading to superresolved images, improving the limit on the finest feature separation by more than a factor of 3.

249 citations


Journal ArticleDOI
TL;DR: It is shown that submicrometer silicon spheres, whose polarizabilities are completely given by their two first Mie coefficients, are an excellent laboratory to test effects of both angle-suppressed and resonant differential scattering cross sections.
Abstract: We show that submicrometer silicon spheres, whose polarizabilities are completely given by their two first Mie coefficients, are an excellent laboratory to test effects of both angle-suppressed and resonant differential scattering cross sections. Specifically, outstanding scattering angular distributions, with zero forward- or backward-scattered intensity, (i.e., the so-called Kerker conditions), previously discussed for hypothetical magnetodielectric particles, are now observed for those Si objects in the near infrared. Interesting new consequences for the corresponding optical forces are derived from the interplay, both in and out of resonance, between the electric- and magnetic-induced dipoles.

224 citations


Journal ArticleDOI
TL;DR: This paper considers antireflective properties of textured surfaces for all texture size-to-wavelength ratios and investigates asymptotic behavior of the reflection with the change of the texture geometry for the long and short wavelength limits.
Abstract: In this paper, we consider antireflective properties of textured surfaces for all texture size-to-wavelength ratios. Existence and location of the global reflection minimum with respect to geometrical parameters of the texture is a subject of our study. We also investigate asymptotic behavior of the reflection with the change of the texture geometry for the long and short wavelength limits. As a particular example, we consider silicon-textured surfaces used in solar cells technology. Most of our results are obtained with the help of the finite-difference time-domain (FDTD) method. We also use effective medium theory and geometric optics approximation for the limiting cases. The FDTD results for these limits are in agreement with the corresponding approximations.

146 citations


Journal ArticleDOI
TL;DR: It is concluded that the anisotropic coefficient influences both the long-term beam spread and the scintillation index by the factor ς(2-α).
Abstract: A wealth of experimental data has shown that atmospheric turbulence can be anisotropic; in this case, a Kolmogorov spectrum does not describe well the atmospheric turbulence statistics. In this paper, we show a quantitative analysis of anisotropic turbulence by using a non-Kolmogorov power spectrum with an anisotropic coefficient. The spectrum we use does not include the inner and outer scales, it is valid only inside the inertial subrange, and it has a power-law slope that can be different from a Kolmogorov one. Using this power spectrum, in the weak turbulence condition, we analyze the impact of the power-law variations α on the long-term beam spread and scintillation index for several anisotropic coefficient values ς. We consider only horizontal propagation across the turbulence cells, assuming circular symmetry is maintained on the orthogonal plane to the propagation direction. We conclude that the anisotropic coefficient influences both the long-term beam spread and the scintillation index by the factor ς2−α.

124 citations


Journal ArticleDOI
TL;DR: A recent linear systems formulation of nonparaxial scalar diffraction theory applied to surface scatter phenomena resulted first in an empirically modified Beckmann-Kirchhoff surface scatter model, then a generalized Harvey-Shack theory that produces accurate results for rougher surfaces than the Rayleigh-Rice theory and for larger incident and scattered angles.
Abstract: Scattering effects from microtopographic surface roughness are merely nonparaxial diffraction phenomena resulting from random phase variations in the reflected or transmitted wavefront. Rayleigh-Rice, Beckmann-Kirchhoff. or Harvey-Shack surface scatter theories are commonly used to predict surface scatter effects. Smooth-surface and/or paraxial approximations have severely limited the range of applicability of each of the above theoretical treatments. A recent linear systems formulation of nonparaxial scalar diffraction theory applied to surface scatter phenomena resulted first in an empirically modified Beckmann-Kirchhoff surface scatter model, then a generalized Harvey-Shack theory that produces accurate results for rougher surfaces than the Rayleigh-Rice theory and for larger incident and scattered angles than the classical Beckmann-Kirchhoff and the original Harvey-Shack theories. These new developments simplify the analysis and understanding of nonintuitive scattering behavior from rough surfaces illuminated at arbitrary incident angles.

120 citations


Journal ArticleDOI
TL;DR: The concept of CASSI is extended to a system admitting multiple shot measurements, which leads not only to higher quality of reconstruction but also to spectrally selective imaging when the sequence of code aperture patterns is optimized.
Abstract: Coded aperture snapshot spectral imaging (CASSI) provides a mechanism for capturing a 3D spectral cube with a single shot 2D measurement. In many applications selective spectral imaging is sought since relevant information often lies within a subset of spectral bands. Capturing and reconstructing all the spectral bands in the observed image cube, to then throw away a large portion of this data, is inefficient. To this end, this paper extends the concept of CASSI to a system admitting multiple shot measurements, which leads not only to higher quality of reconstruction but also to spectrally selective imaging when the sequence of code aperture patterns is optimized. The aperture code optimization problem is shown to be analogous to the optimization of a constrained multichannel filter bank. The optimal code apertures allow the decomposition of the CASSI measurement into several subsets, each having information from only a few selected spectral bands. The rich theory of compressive sensing is used to effectively reconstruct the spectral bands of interest from the measurements. A number of simulations are developed to illustrate the spectral imaging characteristics attained by optimal aperture codes.

113 citations


Journal ArticleDOI
TL;DR: Two novel designs of a multislice channelized Hotelling observer are proposed for the task of detecting 3D signals in 3D images and show that the volumetric model outperforms the others, while the disparity between the models decreases for greater complexity of the detection task.
Abstract: Current clinical practice is rapidly moving in the direction of volumetric imaging. For two-dimensional (2D) images, task-based medical image quality is often assessed using numerical model observers. For three-dimensional (3D) images, however, these models have been little explored so far. In this work, first, two novel designs of a multislice channelized Hotelling observer (CHO) are proposed for the task of detecting 3D signals in 3D images. The novel designs are then compared and evaluated in a simulation study with five different CHO designs: a single-slice model, three multislice models, and a volumetric model. Four different random background statistics are considered, both gaussian (noncorrelated and correlated gaussian noise) and non-gaussian (lumpy and clustered lumpy backgrounds). Overall, the results show that the volumetric model outperforms the others, while the disparity between the models decreases for greater complexity of the detection task. Among the multislice models, the second proposed CHO could most closely approach the volumetric model, whereas the first new CHO seems to be least affected by the number of training samples.

104 citations


Journal ArticleDOI
TL;DR: The SIE-MoM approach is applied only on the material boundary surfaces and interfaces, avoiding the cumbersome volumetric discretization of the objects and the surrounding space required in differential-equation formulations.
Abstract: We present a surface integral equation (SIE) to model the electromagnetic behavior of metallic objects at optical frequencies. The electric and magnetic current combined field integral equation considering both tangential and normal equations is applied. The SIE is solved by using a method-of-moments (MoM) formulation. The SIE-MoM approach is applied only on the material boundary surfaces and interfaces, avoiding the cumbersome volumetric discretization of the objects and the surrounding space required in differential-equation formulations. Some canonical examples have been analyzed, and the results have been compared with analytical reference solutions in order to prove the accuracy of the proposed method. Finally, two plasmonic Yagi–Uda nanoantennas have been analyzed, illustrating the applicability of the method to the solution of real plasmonic problems.

101 citations


Journal ArticleDOI
TL;DR: A simple and effective scene-based nonuniformity correction (NUC) method for infrared focal plane arrays based on interframe registration that estimates the global translation between two adjacent frames and minimizes the mean square error between the two properly registered images.
Abstract: In this paper, we present a simple and effective scene-based nonuniformity correction (NUC) method for infrared focal plane arrays based on interframe registration. This method estimates the global translation between two adjacent frames and minimizes the mean square error between the two properly registered images to make any two detectors with the same scene produce the same output value. In this way, the accumulation of the registration error can be avoided and the NUC can be achieved. The advantages of the proposed algorithm lie in its low computational complexity and storage requirements and ability to capture temporal drifts in the nonuniformity parameters. The performance of the proposed technique is thoroughly studied with infrared image sequences with simulated nonuniformity and infrared imagery with real nonuniformity. It shows a significantly fast and reliable fixed-pattern noise reduction and obtains an effective frame-by-frame adaptive estimation of each detector's gain and offset.

96 citations


Journal ArticleDOI
TL;DR: In this article, the authors provide a comprehensive derivation of a multiple-scattering Monte Carlo UV channel model to study the contribution of different orders of scattering to the path loss and impulse response functions associated with general UV communication system geometries.
Abstract: In large part because of advancements in the design and fabrication of UV LEDs, photodetectors, and filters, significant research interest has recently been focused on non-line-of-sight UV communication systems. This research in, for example, system design and performance prediction, can be greatly aided by accurate channel models that allow for the reproducibility of results, thus facilitating the fair and consistent comparison of different communication approaches. In this paper, we provide a comprehensive derivation of a multiple-scattering Monte Carlo UV channel model, addressing weaknesses in previous treatments. The resulting model can be used to study the contribution of different orders of scattering to the path loss and impulse response functions associated with general UV communication system geometries. Simulation results are provided that demonstrate the benefit of this approach.

89 citations


Journal ArticleDOI
TL;DR: Telecentric architecture is proposed for circumventing, by the pure-optical method, the residual parabolic phase distortion inherent to standard configuration of digital holographic microscopy.
Abstract: Telecentric architecture is proposed for circumventing, by the pure-optical method, the residual parabolic phase distortion inherent to standard configuration of digital holographic microscopy. This optical circumvention produces several important advantages. One is that there is no need for computer compensation of the parabolic phase during the phase map recovering procedure. The other is that in off-axis configuration, the spatial frequency useful domain is enlarged. The validity of the method is demonstrated by performing quantitative measurement of depth differences with high axial resolution.

Journal ArticleDOI
TL;DR: A deterministic regularization algorithm to handle the missing cone problem of three-dimensional optical diffraction tomography (ODT) is discussed and significantly improves the accuracy of the predictions of the refractive index.
Abstract: In this paper, we discuss a deterministic regularization algorithm to handle the missing cone problem of three-dimensional optical diffraction tomography (ODT). The missing cone problem arises in most practical applications of ODT and is responsible for elongation of the reconstructed shape and underestimation of the value of the refractive index. By applying positivity and piecewise-smoothness constraints in an iterative reconstruction framework, we effectively suppress the missing cone artifact and recover sharp edges rounded out by the missing cone, and we significantly improve the accuracy of the predictions of the refractive index. We also show the noise-handling capability of our algorithm in the reconstruction process.

Journal ArticleDOI
TL;DR: In this paper, the optical constants of ion-beam-sputtered SiC films have been measured by ellipsometry in the 190 to 950 nm range, and a good global accuracy of the data was estimated through the use of various sum rules.
Abstract: The optical constants of ion-beam-sputtered SiC films have been measured by ellipsometry in the 190 to 950 nm range. The set of data has been extended both toward shorter and longer wavelengths with data in the literature, along with inter- and extrapolations, in order to obtain a self-consistent set of data by means of Kramers–Kronig analysis. All data correspond to films that were deposited by sputtering on nonheated substrates, and hence they are expected to be amorphous. A bandgap of 1.9 eV for the films was fitted from the obtained optical constants. A good global accuracy of the data was estimated through the use of various sum rules. The consistent dataset includes the visible to the extreme ultraviolet (EUV); this large spectrum of characterization will enable the design of multilayer coatings that combine a high reflectance in parts of the EUV with desired performance at a secondary range, such as the visible. To our knowledge, this paper provides the first compilation of the optical constants of amorphous SiC films.

Journal ArticleDOI
TL;DR: The property of self-healing at the focal plane for both scalar and vector Bessel-Gauss (BG) beams is investigated in the tight focusing condition and recovery of not only intensity but also polarization distribution is observed for an obstructed vector BG beam.
Abstract: The property of self-healing at the focal plane for both scalar and vector Bessel–Gauss (BG) beams is investigated in the tight focusing condition. For the BG beam, which is partially obstructed at the pupil plane, the spatial intensity distribution at the focal plane is well recovered. Furthermore, recovery of not only intensity but also polarization distribution is observed for an obstructed vector BG beam. This self-healing effect for both the intensity and polarization components is recognized even when the half of the beam is obstructed by a semicircular obstacle. The effect of the size of the obstacle on recovery of polarization and intensity distribution is studied. The role of the beam size at the pupil plane is also discussed.

Journal ArticleDOI
TL;DR: A geometrical propagation model is developed that generalizes the classical single-scatter model under the assumption of first-order scattering and non-line-of-sight (NLOS) communication and shows close agreement with Monte Carlo simulation results.
Abstract: In this paper, a geometrical propagation model is developed that generalizes the classical single-scatter model under the assumption of first-order scattering and non-line-of-sight (NLOS) communication. The generalized model considers the case of a noncoplanar geometry, where it overcomes the restriction that the transmitter and the receiver cone axes lie in the same plane. To verify the model, a Monte Carlo (MC) radiative transfer model based on a photon transport algorithm is constructed. Numerical examples for a wavelength of 266 nm are illustrated, which corresponds to a solar-blind NLOS UV communication system. A comparison of the temporal responses of the generalized model and the MC simulation results shows close agreement. Path loss and delay spread are also shown for different pointing directions.

Journal ArticleDOI
TL;DR: In this paper, the Cumulative Reconstructor (CuRe) is adapted to realistic telescope geometries and the transition from modified Hudgin to Fried geometry is discussed, after a discussion of the noise propagation, the complexity of the algorithm is analyzed.
Abstract: The Cumulative Reconstructor (CuRe) is a new direct reconstructor for an optical wavefront from Shack–Hartmann wavefront sensor measurements. In this paper, the algorithm is adapted to realistic telescope geometries and the transition from modified Hudgin to Fried geometry is discussed. After a discussion of the noise propagation, we analyze the complexity of the algorithm. Our numerical tests confirm that the algorithm is very fast and accurate and can therefore be used for adaptive optics systems of Extremely Large Telescopes.

Journal ArticleDOI
TL;DR: It is demonstrated that setting the F parameters of the standardized residual sum of squares index to 1 results in a loss of essential properties of the index, and is therefore strongly discouraged.
Abstract: The standardized residual sum of squares index was proposed to examine the significant merit of a given color-difference formula over another with respect to a given set of visual color-difference data [J. Opt. Soc. Am. A 24, 1823-1829, 2007]. This index can also be employed to determine intra- and inter-observer variability, although the full complexity of this variability cannot be described by just one number. Appropriate utilization of the standardized residual sum of squares index for the assessment of observer variability is described with a view to encourage its use in future color-difference research. The main goal of this paper is to demonstrate that setting the F parameters of the standardized residual sum of squares index to 1 results in a loss of essential properties of the index (for example, symmetry), and is therefore strongly discouraged.

Journal ArticleDOI
TL;DR: A set of representative reconstruction results is discussed to provide numerical evidence of the effectiveness of the proposed algorithmic approach as well as to assess the features and potentialities of the multifocusing integration in comparison with the state-of-the-art SOM implementation.
Abstract: This paper investigates an approach to inverse scattering problems based on the integration of the subspace-based optimization method (SOM) within a multifocusing scheme in the framework of the contrast source formulation. The scattering equations are solved by a nested three-step procedure composed of (a) an outer multiresolution loop dealing with the identification of the regions of interest within the investigation domain through an iterative information-acquisition process, (b) a spectrum analysis step devoted to the reconstruction of the deterministic components of the contrast sources, and (c) an inner optimization loop aimed at retrieving the ambiguous components of the contrast sources through a conjugate gradient minimization of a suitable objective function. A set of representative reconstruction results is discussed to provide numerical evidence of the effectiveness of the proposed algorithmic approach as well as to assess the features and potentialities of the multifocusing integration in comparison with the state-of-the-art SOM implementation.

Journal ArticleDOI
TL;DR: A new generalized modified atmospheric spectral model is derived theoretically for wave propagating through non-Kolmogorov turbulence, which has been reported recently by increasing experimental evidence and theoretical investigation.
Abstract: A new generalized modified atmospheric spectral model is derived theoretically for wave propagating through non-Kolmogorov turbulence, which has been reported recently by increasing experimental evidence and theoretical investigation. The generalized, modified atmospheric spectrum considers finite turbulence inner and outer scales and has a spectral power law value in the range of 3 to 5 instead of the standard power law value of 11/3. When the inner scale and outer scale are set to zero and infinity, respectively, this spectral model is reduced to the classical non-Kolmogorov spectrum.

Journal ArticleDOI
TL;DR: In this paper, the conditions in which polarimetric imaging, which consists of analyzing of the polarization of the light scattered by the scene before forming the image, yields better performance than classical intensity imaging were determined.
Abstract: We consider target detection in images perturbed with additive noise. We determine the conditions in which polarimetric imaging, which consists of analyzing of the polarization of the light scattered by the scene before forming the image, yields better performance than classical intensity imaging. These results give important information to assess the interest of polarimetric imaging in a given application.

Journal ArticleDOI
TL;DR: The waveguide sensitivity of silicon slot microring sensors and single- and double-slot microrings is analyzed using a combination of the effective index and the Airy-functions-based mode matching methods and illustrates that double- slots offer wider fabrication tolerance than single-slot ones.
Abstract: The waveguide sensitivity of silicon slot microring sensors and single- and double-slot microrings is analyzed using a combination of the effective index and the Airy-functions-based mode matching methods. The sensing properties of these two cases are investigated under a variety of geometries. The trends of the waveguide sensitivity on each geometrical parameter are obtained. In addition, the influence of asymmetry on the waveguide sensitivity is also investigated. Calculation also illustrates that double-slot microrings offer wider fabrication tolerance than single-slot ones. These results provide a guideline and insights for designing microring geometry to satisfy the desired sensing requirements and performance.

Journal ArticleDOI
TL;DR: In this article, a very stable approach for finding optical resonances is to solve an eigenvalue equation that evolves from the linearization of the inverse scattering matrix in the Fourier modal method so that advanced coordinate transformation methods such as adaptive spatial resolution and matched coordinates can be included.
Abstract: A very stable approach for finding optical resonances is to solve an eigenvalue equation that evolves from the linearization of the inverse scattering matrix In this paper, we show how to use this approach in the Fourier modal method so that advanced coordinate transformation methods such as adaptive spatial resolution and matched coordinates can be included Furthermore, we present a way that accelerates the computation of the inverse scattering matrix tremendously and allows the derivation of the resonant field distribution inside the structure efficiently

Journal ArticleDOI
TL;DR: A new approach to breast imaging based on the interaction between controlled applied mechanical force and tissue hemodynamics is described, and the expected capabilities and limitations of the developed system are described in relation to the various sensing domains for breast imaging.
Abstract: Imaging studies of the breast comprise three principal sensing domains: structural, mechanical, and functional. Combinations of these domains can yield either additive or wholly new information, depending on whether one domain interacts with the other. In this report, we describe a new approach to breast imaging based on the interaction between controlled applied mechanical force and tissue hemodynamics. Presented is a description of the system design, performance characteristics, and representative clinical findings for a second-generation dynamic near-infrared optical tomographic breast imager that examines both breasts simultaneously, under conditions of rest and controlled mechanical provocation. The expected capabilities and limitations of the developed system are described in relation to the various sensing domains for breast imaging.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a way of computing the Kalman gain for AO systems by means of an approximation that considers the turbulence phase screen as the cropped version of an infinite-size screen.
Abstract: The linear quadratic Gaussian regulator provides the minimum-variance control solution for a linear time-invariant system. For adaptive optics (AO) applications, under the hypothesis of a deformable mirror with instantaneous response, such a controller boils down to a minimum-variance phase estimator (a Kalman filter) and a projection onto the mirror space. The Kalman filter gain can be computed by solving an algebraic Riccati matrix equation, whose computational complexity grows very quickly with the size of the telescope aperture. This “curse of dimensionality” makes the standard solvers for Riccati equations very slow in the case of extremely large telescopes. In this article, we propose a way of computing the Kalman gain for AO systems by means of an approximation that considers the turbulence phase screen as the cropped version of an infinite-size screen. We demonstrate the advantages of the methods for both off- and on-line computational time, and we evaluate its performance for classical AO as well as for wide-field tomographic AO with multiple natural guide stars. Simulation results are reported.

Journal ArticleDOI
TL;DR: In this paper, an optical configuration for parallel two-step phase-shifting digital holographic microscopy (DHM) based on a grating pair is proposed for the purpose of real-time phase microscopy.
Abstract: An optical configuration for parallel two-step phase-shifting digital holographic microscopy (DHM) based on a grating pair is proposed for the purpose of real-time phase microscopy. Orthogonally circularly polarized object and reference waves are diffracted twice by a pair of gratings, and two parallel copies for each beams come into being. Combined with polarization elements, parallel two-step phase-shifting holograms are obtained. Based on the proposed configuration, two schemes of DHM, i.e., slightly off-axis and on-axis DHM, have been implemented. The slightly off-axis DHM suppresses the dc term by subtracting the two phase-shifting holograms from each other, thus the requirement on the off-axis angle and sampling power of the CCD camera is reduced greatly. The on-axis DHM has the least requirement on the resolving power of the CCD camera, while it requires that the reference wave is premeasured and its intensity is no less than 2 times the maximal intensity of the object wave.

Journal ArticleDOI
TL;DR: A first approach of a modal method by Gegenbauer polynomial expansion (MMGE1) is presented for a plane wave diffraction by a lamellar grating and the results obtained are more accurate than several existing modal methods, such as the classical and the parametric FMM.
Abstract: A first approach of a modal method by Gegenbauer polynomial expansion (MMGE1) is presented for a plane wave diffraction by a lamellar grating. Modal methods are among the most popular methods that are used to solve the problem of lamellar gratings. They consist in describing the electromagnetic field in terms of eigenfunctions and eigenvalues of an operator. In the particular case of the Fourier modal method (FMM), the eigenfunctions are approximated by a finite Fourier sum, and this approximation can lead to a poor convergence of the FMM. The Wilbraham–Gibbs phenomenon may be one of the reasons for this poor convergence. Thus, it is interesting to investigate other basis functions that may represent the fields more accurately. The approach proposed in this paper consists in subdividing the pattern in homogeneous layers, according to the periodicity axis. The field is expanded, in each layer, on the basis of Gegenbauer’s polynomials. Boundary conditions are rigorously written between adjacent layers; thus, an eigenvalue equation is obtained. The approach presented in this paper proves to describe the fields accurately. Finally, it is demonstrated that the results obtained with the MMGE1 are more accurate than several existing modal methods, such as the classical and the parametric FMM.

Journal ArticleDOI
TL;DR: The spatial coherence is obtained by Fourier transform of the interferogram generated by the mask when it is illuminated by the light field under analysis.
Abstract: We propose to use a mask with a nonredundant array (NRA) of multiple apertures to measure spatial coherence in two dimensions. The spatial distribution of the apertures in the mask is made in such a way that we obtain a quasi-uniform sampling in the coherence domain. The spatial coherence is obtained by Fourier transform of the interferogram generated by the mask when it is illuminated by the light field under analysis.

Journal ArticleDOI
TL;DR: In this paper, a parametric bidirectional reflectance distribution function (BRDF) model was proposed that can accurately encode a wide variety of real-world isotropic BRDFs with a small number of parameters.
Abstract: We introduce a novel parametric bidirectional reflectance distribution function (BRDF) model that can accurately encode a wide variety of real-world isotropic BRDFs with a small number of parameters. The key observation we make is that a BRDF may be viewed as a statistical distribution on a unit hemisphere. We derive a novel directional statistics distribution, which we refer to as the hemispherical exponential power distribution, and model real-world isotropic BRDFs as mixtures of it. We derive a canonical probabilistic method for estimating the parameters, including the number of components, of this novel directional statistics BRDF model. We show that the model captures the full spectrum of real-world isotropic BRDFs with high accuracy, but a small footprint. We also demonstrate the advantages of the novel BRDF model by showing its use for reflection component separation and for exploring the space of isotropic BRDFs.

Journal ArticleDOI
TL;DR: The degree of polarimetric purity of a Mueller matrix, also called "depolarization index" [Opt. Acta 33, 185 (1986)] is expressed as a quadratic average of two contributions of different nature.
Abstract: The degree of polarimetric purity of a Mueller matrix, also called "depolarization index" [Opt. Acta 33, 185 (1986)] is expressed as a quadratic average of two contributions of different nature. The contribution due to the polarizance and diattenuation properties is given by a unique parameter called "degree of polarizance," and the complementary contribution due to nonpolarizing properties is given by a parameter called "degree of spherical purity." These two intrinsic quantities are useful in order to analyze the sources of the polarimetric purity of a material sample whose Mueller matrix has been measured and provide criteria for the classification of Mueller matrices.

Journal ArticleDOI
TL;DR: In this article, the authors considered the case of a focused fundamental Gaussian beam (TEM(00) mode) illuminating a glass sphere with an eccentrically located spherical water inclusion (having a real refractive index equal to 1.33).
Abstract: Based on the recent results in the generalized Lorenz-Mie theory, solutions for scattering problems of a sphere with an eccentrically located spherical inclusion illuminated by an arbitrary shaped electromagnetic beam in an arbitrary orientation are obtained. Particular attention is paid to the description and application of an arbitrary shaped beam in an arbitrary orientation to the scattering problem under study. The theoretical formalism is implemented in a homemade computer program written in FORTRAN. Numerical results concerning spatial distributions of both internal and external fields are displayed in different formats in order to properly display exemplifying results. More specifically, as an example, we consider the case of a focused fundamental Gaussian beam (TEM(00) mode) illuminating a glass sphere (having a real refractive index equal to 1.50) with an eccentrically located spherical water inclusion (having a real refractive index equal to 1.33). Displayed results are for various parameters of the incident electromagnetic beam (incident orientation, beam waist radius, location of the beam waist center) and of the scatterer system (location of the inclusion inside the host sphere and relative diameter of the inclusion to the host sphere).