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Physical optics

About: Physical optics is a research topic. Over the lifetime, 5342 publications have been published within this topic receiving 101388 citations. The topic is also known as: wave optics.


Papers
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Journal ArticleDOI
TL;DR: Wave interactions, like diffraction and scattering, over the propagation path are described by the uniform theory of diffraction (UTD) and physical optics (PO) and models for rural and urban areas are presented for 2-D and 3-D ray tracing.
Abstract: Mobile communication links are severely influenced by propagation effects. Wave propagation in the VHF/UHF frequency range over natural and man-made terrain is strongly dependent on topography and morphography. Propagation modeling is based on a ray-optical approach. Wave interactions, like diffraction and scattering, over the propagation path are described by the uniform theory of diffraction (UTD) and physical optics (PO). Propagation models for rural and urban areas are presented for 2-D and 3-D ray tracing. Near-range models apply to the corresponding areas in forest and urban sites. The field-strength delay spectrum describes ray contributions with deterministic amplitudes but statistical phases are used to derive time-and frequency-domain channel characteristics. Comparisons between measured and predicted data are presented. >

218 citations

Journal ArticleDOI
TL;DR: To quantitatively assess the new potential of particularly the grating-based dark-field imaging modality, a mathematical formalism together with a material-dependent parameter, the so-called linear diffusion coefficient, is introduced and it is shown that this description can yield quantitative dark- field computed tomography (QDFCT) images of experimental test phantoms.
Abstract: The basic principles of x-ray image formation in radiology have remained essentially unchanged since Rontgen first discovered x-rays over a hundred years ago. The conventional approach relies on x-ray attenuation as the sole source of contrast and draws exclusively on ray or geometrical optics to describe and interpret image formation. Phase-contrast or coherent scatter imaging techniques, which can be understood using wave optics rather than ray optics, offer ways to augment or complement the conventional approach by incorporating the wave-optical interaction of x-rays with the specimen. With a recently developed approach based on x-ray optical gratings, advanced phase-contrast and dark-field scatter imaging modalities are now in reach for routine medical imaging and non-destructive testing applications. To quantitatively assess the new potential of particularly the grating-based dark-field imaging modality, we here introduce a mathematical formalism together with a material-dependent parameter, the so-called linear diffusion coefficient and show that this description can yield quantitative dark-field computed tomography (QDFCT) images of experimental test phantoms.

217 citations

Book
01 Jan 1999

216 citations

Journal ArticleDOI
TL;DR: The detailed optics of photonic nanojets generated by normal plane-wave incidence on dielectric cylinders, which have a subwavelength beam waist and propagate with little divergence for several wavelengths, are discussed.
Abstract: The detailed optics of photonic nanojets generated by normal plane-wave incidence on dielectric cylinders is discussed. These nanojets have a subwavelength beam waist and propagate with little divergence for several wavelengths. A physical explanation for this peculiar behavior is presented. Characteristic dimensions of the nanojets for a large range of physical parameters are calculated.

214 citations

Journal ArticleDOI
TL;DR: In this article, a formulation based on the high frequency asymptotic principles of physical optics is developed for analyzing the scattering by relatively arbitrary open-ended waveguide cavities containing complex interior terminations.
Abstract: A formulation based on the high frequency asymptotic principles of physical optics is developed for analyzing the scattering by relatively arbitrary open-ended waveguide cavities containing complex interior terminations. A magnetic field integral equation (MFIE) is obtained for the equivalent currents on the interior cavity walls and is solved using an iterative physical optics (IPO) algorithm which iteratively applies physical optics to account for multiple reflections inside the cavity. The number of iterations required for convergence is related to the expected number of important reflections. The IPO method is more approximate than a matrix solution of the MFIE, but it is quite accurate for electrically large cavities and is much more efficient. Numerical results are presented which demonstrate the convergence and accuracy of the method by comparison with modal reference solutions. >

212 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202357
2022157
202196
2020140
2019141
2018162