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- Bessel–Gaussian Beams (1)
- Coherent and Partially Coherent Dark Hollow Beams (1)
- Electric potential (1)
- First Born Approximation (1)
- Gaussian Schell-Model (1)
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- Gaussian Schell-model (1)
- Ghost Imaging (1)
- Huygens-Fresnel integral (1)
- Laguerre-Gaussian (LG) beams (1)
- M2-Factor (1)
- Magnetisation (1)
- Magnetoresistance (1)
- Nonuniformly Polarized Beams (1)
- Pair-Structure Factor (1)
- Particulate Medium (1)
- Permalloy (1)
- Rayleigh dielectric sphere (1)
- Scalar Wave Scattering (1)
- Scintillation Index (1)
- Wigner distribution function (1)
Articles 1 - 8 of 8
Full-Text Articles in Physics
Partially Coherent Standard And Elegant Laguerre-Gaussian Beams Of All Orders, Fei Wang, Yangjian Cai, Olga Korotkova
Partially Coherent Standard And Elegant Laguerre-Gaussian Beams Of All Orders, Fei Wang, Yangjian Cai, Olga Korotkova
Physics Articles and Papers
Partially coherent standard and elegant Laguerre-Gaussian (LG) beams of all orders are introduced as a natural extension of coherent standard and elegant LG beams to the stochastic domain. By expanding the LG modes into a finite sum of Hermite-Gaussian modes, the analytical formulae are obtained for the cross-spectral densities of partially coherent standard and elegant LG beams in the source plane and after passing through paraxial ABCD optical system, based on the generalized Collins integral formula. A comparative study of the propagation properties of the partially coherent standard and elegant LG beams in free space is carried out via a …
Radiation Force Of Scalar And Electromagnetic Twisted Gaussian Schell-Model Beams, Chengliang Zhao, Yangjian Cai, Olga Korotkova
Radiation Force Of Scalar And Electromagnetic Twisted Gaussian Schell-Model Beams, Chengliang Zhao, Yangjian Cai, Olga Korotkova
Physics Articles and Papers
Radiation force of a focused scalar twisted Gaussian Schell-model (TGSM) beam on a Rayleigh dielectric sphere is investigated. It is found that the twist phase affects the radiation force and by raising the absolute value of the twist factor it is possible to increase both transverse and longitudinal trapping ranges at the real focus where the maximum on-axis intensity is located. Numerical calculations of radiation forces induced by a focused electromagnetic TGSM beam on a Rayleigh dielectric sphere are carried out. It is found that radiation force is closely related to the twist phase, degree of polarization and correlation factors …
M2-Factor Of Coherent And Partially Coherent Dark Hollow Beams Propagating In Turbulent Atmosphere, Yangsheng Yuan, Yangjian Cai, Jun Qu, Halil T. Eyyuboglu, Yahya Baykal, Olga Korotkova
M2-Factor Of Coherent And Partially Coherent Dark Hollow Beams Propagating In Turbulent Atmosphere, Yangsheng Yuan, Yangjian Cai, Jun Qu, Halil T. Eyyuboglu, Yahya Baykal, Olga Korotkova
Physics Articles and Papers
Analytical formula is derived for the M2-factor of coherent and partially coherent dark hollow beams (DHB) in turbulent atmosphere based on the extended Huygens-Fresnel integral and the second-order moments of the Wigner distribution function. Our numerical results show that the M2- factor of a DHB in turbulent atmosphere increases on propagation, which is much different from its invariant properties in free-space, and is mainly determined by the parameters of the beam and the atmosphere. The relative M2-factor of a DHB increases slower than that of Gaussian and flat-topped beams on propagation, which means a …
Scintillation Of Nonuniformly Polarized Beams In Atmospheric Turbulence, Yalong Gu, Olga Korotkova, Greg Gbur
Scintillation Of Nonuniformly Polarized Beams In Atmospheric Turbulence, Yalong Gu, Olga Korotkova, Greg Gbur
Physics Articles and Papers
We demonstrate, through numerical simulations, that an appropriately chosen nonuniformly polarized coherent optical field can have appreciably smaller scintillation than comparable beams of uniform polarization. This results from the fact that a nonuniformly polarized field acts as an effective two-mode partially coherent field. The results described here are of direct relevance to the development of free-space optical communication systems.
Effect Of The Pair-Structure Factor Of A Particulate Medium On Scalar Wave Scattering In The First Born Approximation, Serkan Sahin, Olga Korotkova
Effect Of The Pair-Structure Factor Of A Particulate Medium On Scalar Wave Scattering In The First Born Approximation, Serkan Sahin, Olga Korotkova
Physics Articles and Papers
Using scattering matrices and the angular spectrum representation of waves, we develop the analytical theory of scattering of random scalar waves from random collections of particles, valid under the first Born approximation. We demonstrate that in the calculation of far-field statistics, such as the spectral density and the spectral degree of coherence, the knowledge of the pair-structure factor of the collection is crucial. We illustrate our analytical approach by considering a numerical example involving scattering of two partially correlated plane waves from a random distribution of spheres.
Scintillation Index Of Modified Bessel–Gaussian Beams Propagating In Turbulent Media, Halil T. Eyyuboglu, Yahya Baykal, Emre Sermutlu, Olga Korotkova, Yangjian Cai
Scintillation Index Of Modified Bessel–Gaussian Beams Propagating In Turbulent Media, Halil T. Eyyuboglu, Yahya Baykal, Emre Sermutlu, Olga Korotkova, Yangjian Cai
Physics Articles and Papers
The scintillation index is formulated for modified Bessel-Gaussian beams propagating in weakly turbulent media. Numerical calculations applied directly to the derived triple integral show that, for off-axis positions, the modified Bessel-Gaussian beams of higher than zero order scintillate less than Gaussian beams at large input beam sizes and low beam orders with the increasing width parameter initially contributing positively to this phenomenon of less scintillation. As the beam order exceeds two, this advantage is diminished. The modified Bessel-Gaussian beam of order zero is a special case, however, exhibiting lowest scintillation at small input beam sizes. When considered against the propagation …
Ghost Imaging With Twisted Gaussian Schell-Model Beam, Yangjian Cai, Qiang Lin, Olga Korotkova
Ghost Imaging With Twisted Gaussian Schell-Model Beam, Yangjian Cai, Qiang Lin, Olga Korotkova
Physics Articles and Papers
Based on the classical optical coherence theory, ghost imaging with twisted Gaussian Schell-model (GSM) beams is analyzed. It is found that the twist phase of the GSM beam has strong influence on ghost imaging. As the absolute value of the twist factor increases, the ghost image disappears gradually, but its visibility increases. This phenomenon is caused by the fact that the twist phase enhances the transverse spatial coherence of the twisted GSM beam on propagation.
Electrical Measurements Of The Polarization In A Moving Magnetic Vortex, Jun-Ichiro Ohe, Stewart E. Barnes, Hyun-Woo Lee, Sadamichi Maekawa
Electrical Measurements Of The Polarization In A Moving Magnetic Vortex, Jun-Ichiro Ohe, Stewart E. Barnes, Hyun-Woo Lee, Sadamichi Maekawa
Physics Articles and Papers
We propose that the polarization of the moving magnetic vortex core can be detected by the electro- and spin-motive forces acting on the spin-polarized conduction electrons. With parameters appropriate to Permalloy, we have simulated the dynamics of a magnetic vortex core resulting from an applied oscillating magnetic field. We show that the polarization of the moving core can be detected by a simple electrical measurement.