Asymptotic solutions for electromagnetic waves in a nonlinear optical cylinder

1996 ◽  
Vol 106 (1) ◽  
pp. 68-74 ◽  
Author(s):  
L. A. Uvarova ◽  
V. K. Fedyanin
Author(s):  
Alexander K. Popov ◽  
Sergey A. Myslivets ◽  
Vitaly V. Slabko ◽  
Victor A. Tkachenko ◽  
Thomas F. George

Backward electromagnetic waves are extraordinary waves with contra-directed phase velocity and energy flux. Unusual properties of the coherent nonlinear optical coupling of the phase-matched ordinary and backward electromagnetic waves with contra-directed energy fluxes are described which enable greatly-enhanced frequency and propagation direction conversion, parametrical amplification, as well as control of shape of the light pulses. Extraordinary transient processes that emerge in such metamaterials in pulsed regimes are described. The results of the numerical simulation of particular plasmonic metamaterials with hyperbolic dispersion are presented, which prove the possibility to match phases of such coupled guided ordinary and backward electromagnetic waves. Particular properties of the outlined processes in the proposed metamaterial are demonstrated through numerical simulations. Potential applications include ultra-miniature amplifiers, frequency changing reflectors, modulators, pulse shapers, and remotely actuated sensors.


2005 ◽  
Vol 2 (13) ◽  
pp. 384-391 ◽  
Author(s):  
Mohsine Khalladi ◽  
M. I. Yaich ◽  
N. Aknin ◽  
M. C. Carrión

This is the first of two papers on the propagation of high-frequency electromagnetic waves through a magnetized plasma in curved space-time. We first show that the nonlinear system of equations governing the plasma and the electromagnetic field in a given, external gravitational field has locally a unique solution for any initial data set obeying the appropriate constraints, and that this system is linearization stable at any of its solu­tions. Next we prove that the linearized perturbations of a ‘background’ solution are characterized by a third-order (not strictly) hyperbolic, constraint-free system of three partial differential equations for three unknown functions of the four space-time coordinates. We generalize the algorithm for obtaining oscillatory asymptotic solutions of linear systems of partial differential equations of arbitrary order, depending polynomially on a small parameter such that it applies to the previously established perturbation equation when the latter is rewritten in terms of dimensionless variables and a small scale ratio. For hyperbolic systems we then state a sufficient condition in order that asymptotic solutions of finite order, constructed as usual by means of a Hamiltonian system of ordinary differential equations for the characteristic strips and a system of transport equations determining the propagation of the amplitudes along the rays, indeed approximate solutions of the system. The pro­cedure is a special case of a two-scale method, suitable for describing the propagation of locally approximately plane, monochromatic waves through a dispersive, inhomogeneous medium. In the second part we shall apply the general method to the perturbation equation referred to above.


2012 ◽  
Vol 77 ◽  
pp. 246-252 ◽  
Author(s):  
Alexander K. Popov ◽  
Mikhail I. Shalaev ◽  
Vitaly V. Slabko ◽  
Sergey A. Myslivets ◽  
Igor S. Nefedov

Novel concepts of nonlinear-optical (NLO) photonic metamaterial are proposed. They concern photonic materials that support backward electromagnetic or vibration waves (BWs) and provide coherent nonlinear-optical energy exchange between ordinary and BWs as applied to three- and four-wave mixing processes. Three different classes of materials which support BWs are considered: plasmonic negative-index (NI) metamaterials (NIMs), metamaterials with specially engineered spatial dispersion of the nanoscopic building blocks, such as standing carbon nanotubes, and crystals that support optical phonons with negative group velocity. The possibility to exploit ordinary crystals instead of plasmonic NLO metamaterials that are very challenging to engineer is proposed. It is shown that extraordinary nonlinear optical frequency-conversion propagation processes attributed to NIMs can be mimicked in the proposed metamaterials. It is also shown that the detrimental effects of strong losses can be mitigated in the short-pulse regimes, which exhibit exotic properties when ordinary and BWs are involved in the NLO coupling. Comparative review of unparallel properties of coherent energy exchange between ordinary and backward electromagnetic waves in NIMs and between ordinary electromagnetic waves coupled through backward vibration waves is given. Unique photonic devices are proposed.


Author(s):  
L. M. Hincapie-Zuluaga ◽  
J. D. Mazo-Vasquez ◽  
C. A. Betancur-Silvera ◽  
Ernesto Reyes-Gomez

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.


Author(s):  
I. H. Musselman ◽  
R.-T. Chen ◽  
P. E. Russell

Scanning tunneling microscopy (STM) has been used to characterize the surface roughness of nonlinear optical (NLO) polymers. A review of STM of polymer surfaces is included in this volume. The NLO polymers are instrumental in the development of electrooptical waveguide devices, the most fundamental of which is the modulator. The most common modulator design is the Mach Zehnder interferometer, in which the input light is split into two legs and then recombined into a common output within the two dimensional waveguide. A π phase retardation, resulting in total light extinction at the output of the interferometer, can be achieved by changing the refractive index of one leg with respect to the other using the electrooptic effect. For best device performance, it is essential that the NLO polymer exhibit minimal surface roughness in order to reduce light scattering. Scanning tunneling microscopy, with its high lateral and vertical resolution, is capable of quantifying the NLO polymer surface roughness induced by processing. Results are presented below in which STM was used to measure the surface roughness of films produced by spin-coating NLO-active polymers onto silicon substrates.


Author(s):  
Anthony S-Y Leong ◽  
David W Gove

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.


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