Search results for " microscopy"
showing 10 items of 1617 documents
Scanning optical microscopy modeling in nanoplasmonics
2012
International audience; One of the main purposes of nanoplasmonics is the miniaturization of optical and electro-optical components that could be integrable in coplanar geometry. In this context, we propose a numerical model of a polarized scanning optical microscope able to faithfully reproduce both photon luminescence and temperature distribution images associated with complex plasmonic structures. The images are computed, pixel by pixel, through a complete self-consistent scheme based on the Green dyadic functions (GDF) formalism. The basic principle consists in the numerical implementation of a realistic three-dimensional light beam acting as a virtual light tip able to probe the volume…
Dispersion relation formalism for the two-photon exchange correction to elastic muon-proton scattering: elastic intermediate state
2018
We evaluate the two-photon exchange correction to the unpolarized cross section in the elastic muon-proton scattering within dispersion relations. One of the six independent invariant amplitudes requires a subtraction. We fix the subtraction function to the model estimate of the full two-photon exchange at one of three MUSE beam energies and make a prediction for the two other energies. Additionally, we present single and double polarization observables accounting for the lepton mass.
Chapter 1 The Resolution Challenge in 3D Optical Microscopy
2009
Publisher Summary This chapter discusses the theoretical principles of 3D microscopy with the widespread realizations of 3D microscopy.Based on the paraxial diffraction equations, it has been shown that conventional microscopes, when dealing with 3D fluorescent samples, provide sets of 2D images. These images of the different transverse sections of the 3D object contain, in addition to the sharp image of the in focus section, the blurred images of the rest of the specimen. The paraxial formalism has been generalized in a very simple way to a non-paraxial context, showing that the equations that govern non-paraxial imaging are similar to those that govern paraxial imaging. The only differenc…
Absolute frequency measurement of rubidium 5S-7S two-photon transitions.
2013
We report the absolute frequency measurements of rubidium 5S-7S two-photon transitions with a cw laser digitally locked to an atomic transition and referenced to an optical frequency comb. The narrow, two-photon transition, 5S-7S (760 nm) insensitive to first order in a magnetic field, is a promising candidate for frequency reference. The performed tests yield the transition frequency with accuracy better than reported previously.
Collinear two-photon excitation of indium rydberg states in a fast atomic beam
1986
The 29p-Rydberg state of neutral indium was produced by double resonant two-photon excitation in a fast atomic beam and detected via field ionization in a longitudinal electric field.
Themes of nanoscience for the introductory physics course
2009
We present three experimental themes and one discussion theme that proved to be suitable for introducing nanoscience through topics that can be integrated into the existing introductory physics or teacher training courses. The experimental themes include two teaching models of an atomic force microscope (AFM) and an experiment with an elastic optical grating. They are all based on simple experiments that give also quantitative results and can be explained using basic physics theory.
4D texture of circular dichroism in soft-x-ray photoemission from tungsten
2019
Brief treatment and crisis intervention 21(1), 013017 (2019). doi:10.1088/1367-2630/aaf4cd
Towards an atomistic understanding of solid friction by computer simulations
2002
Friction between two solid bodies in sliding motion takes place on a large spectrum of length and time scales: From the nanometer/second scale in an atomic force microscope up to the extremely macroscopic scales of tectonic motion. Despite our familiarity with friction, fundamental questions about its atomistic origins remain unanswered. Phenomenological laws that describe the friction in many systems were published more than 300 years ago by Amontons: The frictional force is proportional to the applied load and independent of the apparent area of contact. The atomistic origins of this simple law is still controversial. Many explanations, which seemed to be well-established until recently, …
Strain pattern in supercooled liquids
2016
Investigations of strain correlations at the glass transition reveal unexpected phenomena. The shear strain fluctuations show an Eshelby-strain pattern ($\,\sim \cos{(4\theta)}/r^2\,$), characteristic for elastic response, even in liquids at long times [1]. We address this using a mode-coupling theory for the strain fluctuations in supercooled liquids and data from both, video microscopy of a two-dimensional colloidal glass former and simulations of Brownian hard disks. We show that long-ranged and long-lived strain-signatures follow a scaling law valid close to the glass transition. For large enough viscosities, the Eshelby-strain pattern is visible even on time scales longer than the stru…