This benchmark allows for the quantitative comparison of the trade-offs associated with the three configurations and the impact of key optical parameters, giving useful insight into the choice of parameters and configuration for practical applications of LF-PIV.
The direct reflection amplitudes, r_ss and r_pp, exhibit independence from the signs of the direction cosines associated with the optic axis. Regardless of – or -, the azimuthal angle of the optic axis does not change. In the cross-polarization, the amplitudes r_sp and r_ps display odd behavior; additionally, they conform to the general relationships r_sp(+) = r_ps(+) and r_sp(+) + r_ps(−) = 0. The symmetries encompassing complex reflection amplitudes also uniformly apply to absorbing media, whose refractive indices are complex. For the reflection from a uniaxial crystal at near-normal incidence, analytic expressions for the amplitudes are provided. Corrections to reflection amplitudes (r_ss and r_pp), where polarization remains constant, are found to be of second order with respect to the angle of incidence. At normal incidence, the cross-reflection amplitudes, r_sp and r_ps, exhibit identical values, with corrections that are first-order functions of the angle of incidence, these corrections being equal and opposite in sign. Demonstrations of reflection for non-absorbing calcite and absorbing selenium under various incidence angles are presented, including normal incidence, small-angle (6 degrees), and large-angle (60 degrees).
Through the utilization of Mueller matrix polarization imaging, a novel biomedical optical imaging technique, both polarization and isotropic intensity images of the surface structures of biological tissue samples can be generated. The Mueller matrix of the specimen is determined by a Mueller polarization imaging system in reflection mode, which is further detailed in this paper. Diattenuation, phase retardation, and depolarization are extracted from the specimens using a conventional Mueller matrix polarization decomposition technique and a novel direct method. The analysis indicates a superior speed and practicality of the direct method in comparison to the conventional decomposition method. A method for combining polarization parameters, specifically employing any two of diattenuation, phase retardation, and depolarization, is then described. This approach defines three new quantitative parameters, thereby enabling a more in-depth analysis of anisotropic structures. The introduced parameters' capacity is exemplified by the images of in vitro samples.
A key intrinsic property of diffractive optical elements, wavelength selectivity, displays considerable application potential. Wavelength-specific performance is the central theme, regulating the efficiency distribution across varied diffraction orders for wavelengths spanning from ultraviolet to infrared, employing interlaced dual-layer single-relief blazed gratings constructed from two different materials. To determine the impact of intersecting or partially overlapping dispersion curves on diffraction efficiency in different orders, the dispersion characteristics of inorganic glasses, layered materials, polymers, nanocomposites, and high-index liquids are analyzed, offering a strategy for selecting materials to achieve desired optical performance. Careful selection of material combinations and adjustments to grating depth can allocate a broad array of small or large wavelengths to various diffraction orders with superior efficiency, proving beneficial in wavelength selective optical systems, including tasks like imaging or broadband lighting.
Employing discrete Fourier transforms (DFTs) and a range of other traditional methods, the two-dimensional phase unwrapping problem (PHUP) has seen resolution. No formal solution, based on continuous Fourier transforms and distribution theory, to the continuous Poisson equation for the PHUP, has been reported, as far as we know. This equation's well-established solution, in general terms, results from the convolution of a continuous Laplacian estimate with a particular Green function. This function's Fourier Transform is, however, not mathematically expressible. Alternatively, a Green function, the Yukawa potential, whose Fourier spectrum is guaranteed, can be employed to solve an approximate Poisson equation. This entails a standard FT-based unwrapping approach. Hence, the general methodology for this approach is presented in this work, drawing upon reconstructions from both synthetic and real data sets.
A limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm is applied to the optimization of phase-only computer-generated holograms designed for a multi-depth three-dimensional (3D) target. In lieu of a complete 3D hologram reconstruction, we adopt a novel approach using L-BFGS with sequential slicing (SS) for partial hologram evaluation during optimization, focusing loss calculation on a single slice of the reconstruction per iteration. L-BFGS, owing to its ability to record curvature information, exhibits significant imbalance suppression when the SS technique is utilized.
The phenomenon of light interacting with a two-dimensional collection of homogeneous, spherical particles immersed in a homogeneous, absorbing host medium is examined. A statistical model is used to derive equations describing the optical response of such a system, which includes the impact of multiple light scattering events. The spectral behavior of coherent transmission, reflection, incoherent scattering, and absorption coefficients, in thin films of dielectrics, semiconductors, and metals, encompassing a monolayer of particles with varied spatial organizations, is shown using numerical data. https://www.selleck.co.jp/products/MK-1775.html The host medium material, of which inverse structure particles are composed, and its characteristics are contrasted with the results, and conversely. The redshift of surface plasmon resonance in gold (Au) nanoparticle monolayers, positioned within a fullerene (C60) matrix, is presented as a function of the monolayer filling factor, based on the provided data. The experimental results, as known, find qualitative support in their observations. Future electro-optical and photonic device development may be influenced by these findings.
From Fermat's principle, we provide a detailed derivation of the generalized laws of reflection and refraction, within the context of a metasurface. To begin, we employ the Euler-Lagrange equations to describe the path of a light ray traversing the metasurface. Analytical calculation of the ray-path equation is substantiated by numerical confirmation. We derive generalized laws of reflection and refraction, distinguished by three primary attributes: (i) Their validity encompasses gradient-index and geometrical optics; (ii) Inside the metasurface, multiple reflections coalesce to form a collection of rays exiting the metasurface; (iii) These laws, while rooted in Fermat's principle, deviate from previously established results.
Our approach combines a two-dimensional freeform reflector design with a scattering surface, represented by microfacets—small, specular surfaces depicting surface roughness. The convolution integral of scattered light intensity, as modeled, leads to an inverse specular problem following deconvolution. Accordingly, the design of a reflector with a scattered surface can be computed using deconvolution, subsequently resolving the typical inverse problem in the design of specular reflectors. Reflector radius measurements were influenced by surface scattering, exhibiting a few percentage variation contingent on the scattering degree present within the system.
Inspired by the micro-architecture of the Dione vanillae butterfly's wing scales, we examine the optical responses of two multi-layer structures, possessing one or two corrugated surfaces. A comparison of the reflectance, calculated using the C-method, is made to the reflectance of a planar multilayer. The detailed effect of each geometric parameter on the angular response, which is key for iridescent structures, is carefully examined. This investigation seeks to provide insights for designing multilayered structures, enabling the control of their optical responses.
Real-time phase-shifting interferometry is the focus of this paper's presented method. A customized reference mirror, in the form of a parallel-aligned liquid crystal on a silicon display, underpins this technique. Macropixels are programmed onto the display in preparation for the four-step algorithm, subsequently partitioned into four sections with specific phase adjustments applied to each. https://www.selleck.co.jp/products/MK-1775.html Spatial multiplexing permits the extraction of wavefront phase information at a rate directly constrained by the detector's integration time. To perform a phase calculation, the customized mirror is designed to compensate the initial curvature of the studied object and to introduce the needed phase shifts. Examples of how static and dynamic objects are reconstructed are presented.
A preceding research paper detailed a potent modal spectral element method (SEM), whose unique aspect was its hierarchical basis constructed from modified Legendre polynomials, leading to strong results in the analysis of lamellar gratings. The method, retaining the same ingredients, has been expanded to encompass the broader category of binary crossed gratings in this work. The SEM's geometric adaptability is showcased by gratings whose designs don't conform to the elementary cell's borders. The method is assessed for accuracy through comparison against the Fourier Modal Method (FMM) in the context of anisotropic crossed gratings, and additionally compared to the FMM incorporating adaptive resolution for a square-hole array situated within a silver film.
From a theoretical standpoint, we scrutinized the optical force experienced by a nano-dielectric sphere under the influence of a pulsed Laguerre-Gaussian beam. Under the assumption of dipole approximation, analytical expressions for optical forces were mathematically derived. The optical force's reaction to variations in pulse duration and beam mode order (l,p) was investigated, employing these analytical expressions.