The Experts below are selected from a list of 1401 Experts worldwide ranked by ideXlab platform
Peter Banzer - One of the best experts on this subject based on the ideXlab platform.
-
optical Polarization mobius strips and points of purely transverse spin density
Physical Review Letters, 2016Co-Authors: Thomas Bauer, Peter Banzer, Gerd Leuchs, Martin NeugebauerAbstract:Tightly focused light beams can exhibit complex and versatile structured electric field distributions. The local field may spin around any axis including a transverse axis perpendicular to the beams' propagation direction. At certain focal positions, the corresponding local Polarization Ellipse can even degenerate into a perfect circle, representing a point of circular Polarization or $C$ point. We consider the most fundamental case of a linearly polarized Gaussian beam, where\char22{}upon tight focusing\char22{}those $C$ points created by transversely spinning fields can form the center of 3D optical Polarization topologies when choosing the plane of observation appropriately. Because of the high symmetry of the focal field, these Polarization topologies exhibit nontrivial structures similar to M\"obius strips. We use a direct physical measure to find $C$ points with an arbitrarily oriented spinning axis of the electric field and experimentally investigate the fully three-dimensional Polarization topologies surrounding these $C$ points by exploiting an amplitude and phase reconstruction technique.
Ingo Barth - One of the best experts on this subject based on the ideXlab platform.
-
deformation of atomic p orbitals in strong elliptically polarized laser fields ionization time drifts and spatial photoelectron separation
Physical Review Letters, 2018Co-Authors: Kunlong Liu, Klaus Renziehausen, Janmichael Rost, Ingo BarthAbstract:We theoretically investigate the deformation of atomic p_{±} orbitals driven by strong elliptically polarized (EP) laser fields and the role it plays in tunnel ionization. Our study reveals that different Stark effects induced by orthogonal components of the EP field give rise to subcycle rearrangement of the bound electron density, rendering the initial p_{+} and p_{-} orbitals deformed and polarized along distinctively tilted angles with respect to the Polarization Ellipse of the EP field. As a consequence, the instantaneous tunneling rates change such that for few-cycle EP laser pulses the bound electron initially counterrotating (corotating) with the electric field is most likely released before (after) the peak of the electric field. We demonstrate that with a sequential-pulse setup one can exploit this effect to spatially separate the photoelectrons detached from p_{+} and p_{-} orbitals, paving the way towards robust control of spin-resolved photoemission in laser-matter interactions.
Gerd Leuchs - One of the best experts on this subject based on the ideXlab platform.
-
optical Polarization mobius strips and points of purely transverse spin density
Physical Review Letters, 2016Co-Authors: Thomas Bauer, Peter Banzer, Gerd Leuchs, Martin NeugebauerAbstract:Tightly focused light beams can exhibit complex and versatile structured electric field distributions. The local field may spin around any axis including a transverse axis perpendicular to the beams' propagation direction. At certain focal positions, the corresponding local Polarization Ellipse can even degenerate into a perfect circle, representing a point of circular Polarization or $C$ point. We consider the most fundamental case of a linearly polarized Gaussian beam, where\char22{}upon tight focusing\char22{}those $C$ points created by transversely spinning fields can form the center of 3D optical Polarization topologies when choosing the plane of observation appropriately. Because of the high symmetry of the focal field, these Polarization topologies exhibit nontrivial structures similar to M\"obius strips. We use a direct physical measure to find $C$ points with an arbitrarily oriented spinning axis of the electric field and experimentally investigate the fully three-dimensional Polarization topologies surrounding these $C$ points by exploiting an amplitude and phase reconstruction technique.
Mytyska Kamil - One of the best experts on this subject based on the ideXlab platform.
-
Non-elektricity Quantities Fiber Optic Sensor
Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017Co-Authors: Mytyska KamilAbstract:This diploma thesis deals with an analysis of the method of propagation of optical fiber by two Polarization planes. The method of light propagation is mathematically described using Jones and Stokes vectors. The first part describes wave theory of light divided by Fresnel wave theory, Polarization Ellipse, degenerate Polarization states, parameters of Polarization Ellipse, Poincaré sphere and degenerated states on Poincaré sphere. Then follows Stokes and Jones Polarization parameters, their vectors and Mueller matrix. In addition this paper illustrates the principle of the temperature sensor which is carried out with the help of the polarimeter and its computer program. The following is design of temperature sensor, which is composed of polarizer, photodiode, light output meter and digital multimeter. Another part of the thesis shows the measured values using the current measurement solution using polarimeter and proposed photodiode sensor. At the end of the thesis there is a comparison of the measured values for the three different temperatures that were applied to the optical fiber
-
Non-elektricity Quantities Fiber Optic Sensor
Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017Co-Authors: Mytyska KamilAbstract:Tato diplomová práce se zabývá analýzou způsobu šíření světla optickým vláknem dvěma polarizačními rovinami. Způsob šíření světla je matematicky popsán pomocí Jonesových a Stokesových vektorů. První část práce popisuje vlnovou teorii světla, která je rozdělen na Fresnelovu vlnovou teorii, polarizační elipsu, degenerované polarizační stavy, parametry polarizační elipsy, Poincarého kouli a degenerované stavy na Poincarého kouli. Dále následují Stokesovy a Jonesovy polarizační parametry, jejich vektory a Muellerova matice. Dále tato práce znázorňuje princip senzoru teploty, který je proveden za pomoci polarimetru a jeho počítačového programu. Jako následující je zpracován návrh senzoru teploty, který je sestaven z polarizátoru, fotodiody, měřiče světelného výkonu a digitálního multimetru. Další část práce zobrazuje naměřené hodnoty za použití stávajícího řešení měření pomocí polarimetru a navrhnutého senzoru s fotodiodou. Na konec práce je uvedeno porovnání naměřených hodnot pro tři různé teploty, které působily na optické vlákno.This diploma thesis deals with an analysis of the method of propagation of optical fiber by two Polarization planes. The method of light propagation is mathematically described using Jones and Stokes vectors. The first part describes wave theory of light divided by Fresnel wave theory, Polarization Ellipse, degenerate Polarization states, parameters of Polarization Ellipse, Poincaré sphere and degenerated states on Poincaré sphere. Then follows Stokes and Jones Polarization parameters, their vectors and Mueller matrix. In addition this paper illustrates the principle of the temperature sensor which is carried out with the help of the polarimeter and its computer program. The following is design of temperature sensor, which is composed of polarizer, photodiode, light output meter and digital multimeter. Another part of the thesis shows the measured values using the current measurement solution using polarimeter and proposed photodiode sensor. At the end of the thesis there is a comparison of the measured values for the three different temperatures that were applied to the optical fiber.
D B Milosevic - One of the best experts on this subject based on the ideXlab platform.
-
strong field approximation for ionization of a diatomic molecule by a strong laser field iii high order above threshold ionization by an elliptically polarized field
Physical Review A, 2009Co-Authors: M Busuladžic, A Gazibegovicbusuladžic, D B MilosevicAbstract:We investigate high-order above-threshold ionization (HATI) of diatomic molecules having different symmetries by an elliptically polarized laser field using the modified molecular strong-field approximation. The yields of high-energy electrons contributing to the plateau region of the photoelectron spectra strongly depend on the employed ellipticity. This is more pronounced if the major axis of the Polarization Ellipse is parallel or perpendicular to the molecular axis and at the end of the high-energy plateau. For the ${\text{O}}_{2}$ molecule (characterized by ${\ensuremath{\pi}}_{\text{g}}$ symmetry) the maximum yield is observed for some value of the ellipticity $\ensuremath{\epsilon}$ different from zero. On the other hand, in the same circumstances, the ${\text{N}}_{2}$ molecule $({\ensuremath{\sigma}}_{\text{g}})$ behaves as an atom, i.e., the yield is maximum for $\ensuremath{\epsilon}=0$. These characteristics of the photoelectron spectra remain valid in a wide region of the molecular orientations and laser peak intensities. The symmetry properties of the molecular HATI spectra are considered in detail: by changing the molecular orientation one or other type of the symmetry emerges or disappears. Presenting differential ionization spectra in the ionized electron energy-emission angle plane we have observed similar interference effects as in the HATI spectra governed by a linearly polarized field.