Journal ArticleDOI
Physical optics treatment of the shadowgraph
TLDR
In this article, the authors present an analysis of the shadowgraph method of visualizing convective flows based on physical optics, treating the refractive-index perturbation caused by the flow as a transmission grating.Abstract:
We present an analysis of the shadowgraph method of visualizing convective flows based on physical optics, treating the refractive-index perturbation caused by the flow as a transmission grating. Various patterns in thermal convection of an isotropic fluid as well as normal rolls in electroconvection of a nematic liquid crystal are considered. The results differ significantly from those of geometrical optics, showing that use of the shadowgraph as a quantitative tool for amplitude measurements should not, in general, be based on geometrical optics.read more
Citations
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Book ChapterDOI
Chemical Physics of Colloid Systems and Interfaces
TL;DR: In this article, the authors consider the interaction between a Particle of Immobile Surface Interacting with a Solid Wall 5.5.2 and Fluid Particles and Films of Tangentially Mobile Surfaces.
Journal ArticleDOI
Scattering information obtained by optical microscopy: differential dynamic microscopy and beyond.
TL;DR: A theoretical model for microscope imaging is derived that accounts for the three-dimensional nature of the sample, the arbitrary coherence properties of the light source, and the effect of the finite numerical aperture of the microscope objective and extends to the class of microscopy techniques that can be described by a linear space-invariant imaging of the density of the scattering centers, which includes, for example, dynamic fluorescence microscopy.
Journal ArticleDOI
X-ray-scattering information obtained from near-field speckle
Roberto Cerbino,L. Peverini,Marco A. C. Potenza,Aymeric Robert,Aymeric Robert,P. Bösecke,Marzio Giglio +6 more
TL;DR: In this article, it was shown that, in spite of the limited spatial coherence of synchrotron radiation, speckles with remarkable properties can be observed when the sensor is placed in the near field.
Journal ArticleDOI
Fractal fronts of diffusion in microgravity
Alberto Vailati,Roberto Cerbino,Stefano Mazzoni,Stefano Mazzoni,Christopher J. Takacs,David S. Cannell,Marzio Giglio +6 more
TL;DR: Experimental results obtained in microgravity during the flight of the FOTON M3 satellite find that during a diffusion process a dilute polymer solution exhibits scale-invariant concentration fluctuations with sizes ranging up to millimetres, and relaxation times as large as 1,000 s.
References
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Book
Principles of Optics
TL;DR: In this paper, the authors discuss various topics about optics, such as geometrical theories, image forming instruments, and optics of metals and crystals, including interference, interferometers, and diffraction.
Principles of Optics
TL;DR: In this article, the authors discuss various topics about optics, such as geometrical theories, image forming instruments, and optics of metals and crystals, including interference, interferometers, and diffraction.
Journal ArticleDOI
Rigorous coupled-wave analysis of planar-grating diffraction
M. G. Moharam,Thomas K. Gaylord +1 more
TL;DR: In this article, a rigorous coupled-wave approach is used to analyze diffraction by general planar gratings bounded by two different media, and the analysis is based on a state-variables representation and results in a unifying, easily computer-implementable matrix formulation.