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Related papers: Why is the refractive index cannot be negative

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This work demonstrates the existence of both negative refraction and a negative refractive index in an optical uniaxial absorbent medium that can be characterized by ordinary and extraordinary refractive indices. Negative refraction occurs…

Optics · Physics 2009-05-04 Yi-Jun Jen , Ching-Wei Yu , Chin-Te Lin

The sign of the refractive index of any medium is soley determined by the requirement that the propagation of an electromagnetic wave obeys Einstein causality. Our analysis shows that this requirement predicts that the real part of the…

Optics · Physics 2009-11-10 Yi-Fan Chen , Peer Fischer , Frank W. Wise

The set of realizable refractive indices as a function of frequency is considered. For passive media we give bounds for the refractive index variation in a finite bandwidth. Special attention is given to the loss and index variation in the…

Optics · Physics 2009-11-11 Johannes Skaar , Kristian Seip

Wave refraction in negative-index media is always negative.

Condensed Matter · Physics 2007-05-23 W. T. Lu , J. B. Sokoloff , S. Sridhar

The physical origins of negative refractive index are derived from a dilute microscopic model, producing a result that is generalized to the dense condensed phase limit. In particular, scattering from a thin sheet of electric and magnetic…

Optics · Physics 2009-11-10 David W. Ward , Keith A. Nelson , Kevin J. Webb

The identification of the refractive index and wave vector for general (possibly active) linear, isotropic, homogeneous, and non-spatially dispersive media is discussed. Correct conditions for negative refraction necessarily include the…

Optics · Physics 2009-11-13 Johannes Skaar

Here I present an overview of recent studies of the phenomenon of negative refraction and left-handed materials. I will discuss some basic questions pertinent to the problem. It is pointed out that the current claims of negative refraction…

Materials Science · Physics 2007-05-23 Zhen Ye

Negative-index refraction is achieved in a lamellar composite with epsilon-negative (ENG) and mu-negative (MNG) materials stacked alternatively. Based on the effective medium approximation, simultaneously negative effective permittivity and…

Optics · Physics 2009-11-11 Z. G. Dong , S. N. Zhu , H. Liu

The optical refractive index of a moving regular medium is calculated by using the Lorentz transformation in this note. It is shown that in some velocity region of medium moving relative to the initial frame K, the moving medium may possess…

Classical Physics · Physics 2007-05-23 Jian Qi Shen

We discuss and clarify some misleading statements appeared in a recent article on negative refraction in metamaterials. In this comment, we straighten the physical meaning and underlying phenomena behind negative refraction and negative…

Optics · Physics 2012-10-17 George Eleftheriades , Andrea Alu

The race to engineering metamaterials comprising of a negative refractive index in the optical range has been fueled by the realization of negative index materials for GHz frequencies six years ago. Sheer miniaturization of the GHz resonant…

Recently, artificially constructed metamaterials have become of considerable interest, as these materials can exhibit electromagnetic characteristics unlike any conventional materials. Artificial magnetism and negative refractive index are…

Optics · Physics 2025-07-09 D. R. Smith , J. B. Pendry , M. C. K. Wiltshire

A key optical parameter characterizing the existence of negative refraction in a thin layer of a composite material is the effective refractive index of an equivalent, homogenized layer with the same physical thickness as the initial…

Negative refraction is known to occur in materials that simultaneously possess a negative electric permittivity and magnetic permeability; hence they are termed negative index materials. However, there are no known natural materials that…

We argue that the widely spread opinion that the left-handed media (LHM) are characterized by a negative refractive index $n_-$ is misleading. Since n does not enter into Maxwell's equations and boundary conditions, any medium may be…

Condensed Matter · Physics 2009-11-07 A. L. Pokrovsky , A. L. Efros

In this Letter the expression for the refractive index of de Broglie wave in the presence of a potential field is obtained and based on this, the physical meanings of negative index of refraction is revealed. We demonstrate that the…

Materials Science · Physics 2007-05-23 Jian Qi Shen

The paper considers an opportunity for the creation of an artificial two-component metamaterial with a negative refractive index within the radio and optical frequency band, which possesses a spatial dispersion. It is shown that there…

Optics · Physics 2008-04-28 V. V. Slabko

We analyze refraction of electromagnetic wave packets on passing from an isotropic positive to an isotropic negative refractive index medium. We definitively show that in all cases the energy is always refracted negatively. For localized…

Condensed Matter · Physics 2007-05-23 W. T. Lu , J. B. Sokoloff , S. Sridhar

We further miniaturize a recently established silver-based negative-index metamaterial design. By comparing transmittance, reflectance and phase-sensitive time-of-flight experiments to theory, we infer a real part of the refractive index of…

Optics · Physics 2009-11-13 Gunnar Dolling , Martin Wegener , Costas M. Soukoulis , Stefan Linden

Specially designed metal-dielectric composites can have a negative refractive index in the optical range. Specifically, it is shown that arrays of single and paired nanorods can provide such negative refraction. For pairs of metal rods, a…

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