scholarly journals Characterization of the Vortex Beam by Fermat’s Spiral

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 102
Author(s):  
Ewa Frączek ◽  
Agnieszka Popiołek-Masajada ◽  
Sławomir Szczepaniak
Keyword(s):  
Phase Distribution ◽  
Phase Plate ◽  
Vortex Beam ◽  
Scanning Microscope ◽  
Object Beam ◽  
Fitting Method ◽  
Numerical Fitting ◽  
Helical Beam ◽  
Spiral Phase

In this paper, we characterize the helical beam structure through an analysis of the spiral character of the phase distribution inside a light beam. In particular, we show that a line connected with the 2π phase jump in the Laguerre–Gauss beam can be described by a Fermat’s spiral. We propose a numerical fitting method to determine the parameters of a spiral equation for the phase distribution of the helical beam. Next, we extend the procedure to a vortex beam created by the spiral phase plate and apply it to experimental phase maps, which allows us to recover the phase shift introduced into the object beam in the optical vortex scanning microscope.

scholarly journals Spiral phase plate with multiple singularity centers

2020 ◽  
Vol 44 (6) ◽  
pp. 901-908
Author(s):  
V.V. Kotlyar ◽  
A.A. Kovalev ◽  
E.S. Kozlova ◽  
A.P. Porfirev
Keyword(s):  
Topological Charge ◽  
Beam Power ◽  
Phase Plate ◽  
Circular Aperture ◽  
Vortex Beam ◽  
Finite Radius ◽  
Phase Singularity ◽  
Initial Plane ◽  
Topological Charges ◽  
Spiral Phase

We investigate a multispiral phase plate (MSPP) with multiple centers of phase singularity arbitrarily located in the MSPP plane. Equations to describe the topological charge of an optical vortex in the initial plane immediately behind the MSPP and orbital angular momentum (OAM) normalized relative to the beam power are derived. The topological charge in the initial plane is found as a sum of the topological charges of all singularities if their centers are located inside a finite-radius circular aperture. If the phase singularity centers are partially located on the boundary of a circular diaphragm limiting the MSPP, the total topological charge is found as the sum of all singularities divided by 2. Total OAM that the vortex carries depends on the location of the singularity centers: the farther from the center of the plate the singularity center is located, the smaller is its contribution to the OAM. If all singularity centers are located on the boundary of the diaphragm limiting MSPP, then the OAM of the vortex beam equals zero, although in this case the topological charge of the beam is nonzero.

scholarly journals High-speed format 1000BASE-SX / LX transmission through the atmosphere by vortex beams near IR range with help modified SFP-transmers DEM-310GT

2020 ◽  
Vol 44 (4) ◽  
pp. 578-581
Author(s):  
S.V. Karpeev ◽  
V.V. Podlipnov ◽  
N.A. Ivliev ◽  
S.N. Khonina
Keyword(s):  
Optical Communication ◽  
High Speed ◽  
Near Infrared ◽  
Phase Plate ◽  
Vortex Beam ◽  
Optical Communication System ◽  
Near Ir ◽  
Vortex Beams ◽  
Spiral Phase ◽  
Near Ir Range

The possibility of constructing a near-infrared atmospheric optical communication system based on a pair of media converters of a signal format 100Base-TX / 1000BASE-T to format 1000BASE-SX / LX with SFP transceivers DEM-310GT was experimentally investigated. The FAN-OUT TUBING FTB900 SN-Y4 fiber cable connector, coming from the receiving radiation collimator for matching with the DEM-310GT transceiver, was modified. The transmitting radiation collimator is supplemented by a spiral phase plate to form a vortex beam. The influence of atmospheric influence on the data rate is analyzed.

Generation and Interference of Vortex Beam Based on Spiral Phase Plate

2016 ◽  
Vol 53 (9) ◽  
pp. 092602
Author(s):  
郭苗军 Guo Miaojun ◽  
曾军 Zeng Jun ◽  
李晋红 Li Jinhong
Keyword(s):  
Phase Plate ◽  
Vortex Beam ◽  
Spiral Phase Plate ◽  
Spiral Phase

scholarly journals Production of Vortex Beam Modes from a Magnetic Spiral Phase Plate

2013 ◽  
Vol 19 (S2) ◽  
pp. 1168-1169
Author(s):  
A.M. Blackburn ◽  
J.C. Loudon
Keyword(s):  
Phase Plate ◽  
Vortex Beam ◽  
Spiral Phase Plate ◽  
Magnetic Spiral ◽  
Spiral Phase

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

scholarly journals Direct observation of the topological charge of a terahertz vortex beam generated by a Tsurupica spiral phase plate

2014 ◽  
Vol 104 (26) ◽  
pp. 261104 ◽  
Author(s):  
K. Miyamoto ◽  
K. Suizu ◽  
T. Akiba ◽  
T. Omatsu
Keyword(s):  
Direct Observation ◽  
Topological Charge ◽  
Phase Plate ◽  
Vortex Beam ◽  
Spiral Phase Plate ◽  
Spiral Phase
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