Multi-spot focal pattern formation and beam reshaping by mixing square-shaped and hexagonal vortex lattices

2019 ◽  
Author(s):  
Lyubomir Stoyanov ◽  
Georgi Maleshkov ◽  
Maya Zhekova ◽  
Ivan Stefanov ◽  
Gerhard G. Paulus ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Vortex Lattices ◽  
Focal Pattern

Far-field pattern formation by manipulating the topological charges of square-shaped optical vortex lattices

2018 ◽  
Vol 35 (2) ◽  
pp. 402 ◽  
Author(s):  
L. Stoyanov ◽  
G. Maleshkov ◽  
M. Zhekova ◽  
I. Stefanov ◽  
D. N. Neshev ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Optical Vortex ◽  
Field Pattern ◽  
Far Field ◽  
Vortex Lattices ◽  
Far Field Pattern ◽  
Topological Charges

Real-time observation of vortex lattices in a superconductor

1993 ◽  
Vol 51 ◽  
pp. 1050-1051
Author(s):  
K. Harada ◽  
T. Matsuda ◽  
J.E. Bonevich ◽  
M. Igarashi ◽  
S. Kondo ◽  
...  
Keyword(s):  
Real Time ◽  
Flux Line ◽  
Electron Holography ◽  
Lorentz Microscopy ◽  
Vortex Lattices ◽  
Flux Lines ◽  
Magnetic Flux Lines ◽  
Time Observation ◽  
Thin Superconductor ◽  
Real Time Observation

Previous observations of magnetic flux-lines (vortex lattices) in superconductors, such as the field distribution of a flux-line, and flux-line dynamics activated by heat and current, have employed the high spatial resolution and magnetic sensitivity of electron holography. And recently, the 2-D static distribution of vortices was also observed by this technique. However, real-time observations of the vortex lattice, in spite of scientific and technological interest, have not been possible due to experimental difficulties. Here, we report the real-time observation of vortex lattices in a thin superconductor, by means of Lorentz microscopy using a 300 kV field emission electron microscope. This technique allows us to observe the dynamic motion of individual vortices and record the events on a VTR system.The experimental arrangement is shown in Fig. 1. A Nb thin film for transmission observation was prepared by chemical etching. The grain size of the film was increased by annealing, and single crystals were observed with a thickness of 50∼90 nm.

Pattern formation in the splay Freedericks transition of a nematic side-group polysiloxane

1993 ◽  
Vol 3 (6) ◽  
pp. 865-889 ◽  
Author(s):  
Norbert Schwenk ◽  
Hans Wolfgang Spiess
Keyword(s):  
Pattern Formation ◽  
Side Group

Pattern Formation in Thin Polymer Films: A New Morphology

2000 ◽  
Vol 629 ◽  
Author(s):  
Jean-Loup Masson ◽  
Peter F. Green
Keyword(s):  
Growth Rate ◽  
Pattern Formation ◽  
Early Stage ◽  
Structural Evolution ◽  
Distinct Form ◽  
Thin Polymer Films ◽  
Intermediate Morphology ◽  
Thin Polymer ◽  
Nonwetting Liquid ◽  
Cylindrical Holes

ABSTRACTResearchers have shown that thin, nonwetting, liquid homopolymer films dewet substrates, forming patterns that reflect fluctuations in the local film thickness. These patterns have been shown to be either discrete cylindrical holes or bicontinuous “spinodal-like” patterns. In this paper we show the existence of a new morphology. During the early stage of dewetting, discrete highly asymmetric holes appear spontaneously throughout the film. The nucleation rate of these holes is faster than their growth rate. The morphology of the late stage of evolution, after 18 days, is characterized by a bicontinuous pattern, distinct form conventional spinodal dewetting patterns. This morphology has been observed for a range of film thicknesses between 7.5 and 21nm. The structural evolution of this intermediate morphology is discussed.

Pattern Formation Survey on Non Uniformly Forced Swift-Hohenberg Equation

2019 ◽  
Author(s):  
Daniel Coelho ◽  
José da Rocha Miranda Pontes ◽  
Norberto Mangiavacchi
Keyword(s):  
Pattern Formation
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