Electromagnetic Waves in Free Space

2004 ◽  
pp. 351-374
Author(s):  
J. A. Bittencourt
Keyword(s):  
Free Space ◽  
Electromagnetic Waves

Determination of the velocity of short electromagnetic waves by interferometry

1952 ◽  
Vol 213 (1112) ◽  
pp. 123-141 ◽  
Keyword(s):  
Phase Velocity ◽  
Electromagnetic Radiation ◽  
Free Space ◽  
Electromagnetic Waves ◽  
Wave Beam ◽  
Wave Length ◽  
Wave Frequency ◽  
Space Wave

A new measurement of the velocity of electromagnetic radiation is described. The result has been obtained, using micro-waves at a frequency of 24005 Mc/s ( λ = 1∙25 cm), with a form of interferometer which enables the free-space wave-length to be evaluated. Since the micro-wave frequency can also be ascertained, phase velocity is calculated from the product of frequency and wave-length. The most important aspect of the experiment is the application to the measured wave-length of a correction which arises from diffraction of the micro-wave beam. This correction is new to interferometry and is discussed in detail. The result obtained for the velocity, reduced to vacuum conditions, is c 0 = 299792∙6 ± 0∙7 km/s.

On Mechanics of Light Propagation in Free Space with Final Temperature

2007 ◽  
Vol 3 (2) ◽  
pp. 220-231
Author(s):  
M. Ja. Ivanov ◽  
V.K. Mamaev
Keyword(s):  
Exact Solutions ◽  
Free Space ◽  
Electromagnetic Waves ◽  
Light Propagation ◽  
Longitudinal Component ◽  
Final Temperature ◽  
Final Density ◽  
Propagation Of Light ◽  
Waves Propagation ◽  
Modified Theory

Features of electromagnetic waves propagation of light range are considered in free space with final temperature 2.725K. The presence in space of temperature (and final density) allows justification to introduce the longitudinal component of electromagnetic field. A modified theory of electromagnetic waves propagation in free space is offered.  Exact solutions of the nonlinear equations system in the presence of electric and gasdynamic interaction are obtained. Some of demonstrated exact solutions have a nature of continues and decretive spectrum.

scholarly journals Topologically protected broadband rerouting of propagating waves around complex objects

Nanophotonics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 1371-1378 ◽  
Author(s):  
Zeki Hayran ◽  
Seyyed Ali Hassani Gangaraj ◽  
Francesco Monticone
Keyword(s):  
Free Space ◽  
Electromagnetic Waves ◽  
Guided Waves ◽  
Plane Waves ◽  
Transmission Efficiency ◽  
Wave Radiation ◽  
Isotropic Layer ◽  
Complex Objects ◽  
Plasmonic Material ◽  
Propagating Waves

AbstractAchieving robust propagation and guiding of electromagnetic waves through complex and disordered structures is a major goal of modern photonics research, for both classical and quantum applications. Although the realization of backscattering-free and disorder-immune guided waves has recently become possible through various photonic schemes inspired by topological insulators in condensed matter physics, the interaction between such topologically protected guided waves and free-space propagating waves remains mostly unexplored, especially in the context of scattering systems. Here, we theoretically demonstrate that free-space propagating plane waves can be efficiently coupled into topological one-way surface waves, which can seamlessly flow around sharp corners and electrically large barriers and release their energy back into free space in the form of leaky-wave radiation. We exploit this physical mechanism to realize topologically protected wave-rerouting around an electrically large impenetrable object of complex shape, with transmission efficiency exceeding 90%, over a relatively broad bandwidth. The proposed topological wave-rerouting scheme is based on a stratified structure composed of a topologically nontrivial magnetized plasmonic material coated by a suitable isotropic layer. Our results may open a new avenue in the field of topological photonics and electromagnetics, for applications that require engineered interactions between guided waves and free-space propagating waves, including for complex beam-routing systems and advanced stealth technology. More generally, our work may pave the way for robust defect/damage-immune scattering and radiating systems.

SCATTERING OF ELECTROMAGNETIC WAVES BY A MOVING CYLINDER IN FREE SPACE

1967 ◽  
Vol 45 (9) ◽  
pp. 2999-3007 ◽  
Author(s):  
S. W. Lee ◽  
R. Mittra
Keyword(s):  
Angular Dependence ◽  
Lorentz Transformation ◽  
Doppler Shift ◽  
Free Space ◽  
Electromagnetic Waves ◽  
Stationary Problem ◽  
Small Radius ◽  
Far Field ◽  
Field Patterns ◽  
Moving Cylinder

Scattering of electromagnetic waves by a moving cylinder in free space is studied by an application of Lorentz transformation. It is shown that the solution in the transformed coordinates can be derived readily from a knowledge of the solution of the corresponding stationary problem. Several important characteristics of the scattered far-fields are investigated in detail for a cylinder of small radius. These include the calculation of the far-field patterns and the angular dependence of the Doppler shift.

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