Wave packets, the Poynting vector, and energy flow: 2. Group propagation through dissipative isotropic media

1951 ◽  
Vol 56 (2) ◽  
pp. 197-206 ◽  
Author(s):  
C. O. Hines
Keyword(s):  
Energy Flow ◽  
Poynting Vector ◽  
Wave Packets ◽  
Isotropic Media

Investigation of energy conversion processes and wave activity related to dipolarization fronts observed by MMS

2021 ◽  
Author(s):  
Soboh Alqeeq ◽  
Olivier Le Contel ◽  
Patrick Canu ◽  
Alessandro Retino ◽  
Thomas Chust ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Energy Flow ◽  
Poynting Vector ◽  
Wave Activity ◽  
Electromagnetic Energy ◽  
Particle Measurements ◽  
Dipolarization Front ◽  
The Earth ◽  
Current Densities ◽  
Scale Properties

<p>In the present work, we consider four dipolarization front (DF) events detected by MMS spacecraft in the Earth’s magnetotail during a substorm on 23rd of July 2017 between 16:05 and 17:19 UT. From their ion scale properties, we show that these four DF events embedded in fast Earthward plasma flows have classical signatures with increases of Bz, velocity and temperature and a decrease of density across the DF. We compute and compare current densities obtained from magnetic and particle measurements and analyse the Ohm’s law. Then we describe the wave activity related to these DFs. We investigate energy conversion processes via J.E calculations and estimate the importance of the electromagnetic energy flow by computing the divergence of the Poynting vector. Finally we discuss the electromagnetic energy conservation in the context of these DFs.</p>

scholarly journals Vortex energy flow in the tight focus of a non-vortex field with circular polarization

2020 ◽  
Vol 44 (1) ◽  
pp. 5-11
Author(s):  
V.V. Kotlyar ◽  
S.S. Stafeev ◽  
A.G. Nalimov
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Energy Flow ◽  
Poynting Vector ◽  
Focal Spot ◽  
Free Field ◽  
Longitudinal Component ◽  
Circularly Polarized ◽  
Linearly Polarized ◽  
Direct Energy

Using Richards-Wolf formulas, we show that an axisymmetric circularly polarized vortex-free field can be focused into a sharp subwavelength focal spot, around which there is a region where the light energy flow propagates along a spiral. This effect can be explained by the conversion of the spin angular momentum of the circularly polarized field into the orbital angular momentum near the focus, although the on-axis orbital angular momentum remains zero. It is also shown that a linearly polarized optical vortex with topological charge 2 forms near the focal plane an on-axis reverse energy flow (defined by the negative longitudinal component of the Poynting vector) whose amplitude is comparable with the direct energy flow.

The Poynting vector field and the energy flow within a transformer

1986 ◽  
Vol 54 (6) ◽  
pp. 528-531 ◽  
Author(s):  
F. Herrmann ◽  
G. Bruno Schmid
Keyword(s):  
Vector Field ◽  
Energy Flow ◽  
Poynting Vector

scholarly journals Formation of an elongated region of energy backflow using ring apertures

2019 ◽  
Vol 43 (2) ◽  
pp. 193-199
Author(s):  
S.S. Stafeev ◽  
V.V. Kotlyar
Keyword(s):  
Energy Flow ◽  
Poynting Vector ◽  
Numerical Aperture ◽  
Second Order ◽  
Depth Of Focus ◽  
Incident Wavelength ◽  
Entrance Pupil ◽  
High Numerical Aperture ◽  
Vector Beam ◽  
Cylindrical Vector Beam

In this paper, we have investigated the focusing of a second-order cylindrical vector beam by using a high numerical aperture (NA) lens limited by a ring aperture using the Richards-Wolf formulae. It was shown that the range of negative on-axis projections of the Poynting vector could be increased by increasing the depth of focus through the use of a ring aperture. It was shown that when focusing light with a lens with NA = 0.95, the use of a ring aperture limiting the entrance pupil angle to 0.9 of maximum, allows the depth of the region of negative on-axis Poynting vector projections to be four times increased, with the region width remaining almost unchanged and varying from 0.357 to 0.352 of the incident wavelength. Notably, the magnitude of the reverse energy flow was found to be larger than the direct one by a factor of 2.5.

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