|
This article is cited in 3 scientific papers (total in 3 papers)
OPTO-IT
Birth of optical vortices in propagating fields with an original fractional topological charge
V. V. Kotlyarab, A. A. Kovalevab, A. P. Porfirevab a IPSI RAS – Branch of the FSRC "Crystallography and Photonics" RAS,
443001, Samara, Russia, Molodogvardeyskaya 151
b Samara National Research University, 443086, Samara, Russia, Moskovskoye Shosse 34
Abstract:
In contrast to the orbital angular momentum (OAM), which is conserved on free space propagation, the topological charge (TC) of a paraxial optical vortex (OV) is not conserved in the general case. Here, we investigate a Gaussian beam with a fractional TC in the original plane and demonstrate both theoretically and numerically how the TC changes in the course of propagation. Depending on the proximity of the topological charge to an even or odd integer number, an optical vortex with the original fractional TC is shown to behave in a number of different ways. For simple OVs (Laguerre-Gaussian or Bessel-Gaussian modes), TC is conserved both in propagation and after weak phase distortions. An experiment shows that when scattered by a random phase screen, the integer TC of an OV is conserved right up to a random phase variation of $\pi$. Therefore, in the case of weak turbulences, it is expedient to measure a discretely varying TC instead of a continuously varying OAM.
Keywords:
optical vortex, fractional topological charge, near-field diffraction, Fresnel diffraction, far-field diffraction.
Received: 05.03.2020 Accepted: 29.04.2020
Citation:
V. V. Kotlyar, A. A. Kovalev, A. P. Porfirev, “Birth of optical vortices in propagating fields with an original fractional topological charge”, Computer Optics, 44:4 (2020), 493–500
Linking options:
https://www.mathnet.ru/eng/co813 https://www.mathnet.ru/eng/co/v44/i4/p493
|
Statistics & downloads: |
Abstract page: | 122 | Full-text PDF : | 56 | References: | 11 |
|