Negative refraction in a uniaxial absorbent dielectric material

Abstract

Refraction of light from an isotropic dielectric medium to an anisotropic dielectric material is a complicated phenomenon that can have several different characteristics not usually discussed in electromagnetics textbooks for undergraduate students. With a simple problem wherein the refracting material is uniaxial with its optic axis normal to the interface plane, the phenomena of (i) negative/positive refraction, (ii) negative/positive phase velocity, (iii) counterposition of the phase velocity and the time-averaged Poynting vector, and (iv) 'negative refraction' of the energy flux density can be examined. The last-named phenomenon is really negative deflection by refraction.

Conditions of Perfect Imaging in Negative Refraction Materials with Gain

“…Negative refraction is known to offer a wide range of potential applications [1][2][3][4]. However, losses, which are an inherent feature of the negative refraction, present a major impediment to the performance of NRMs [5][6][7][8][9]. To overcome these problems, NRMs with gain were proposed to compensate the losses, even to turn the materials into amplified systems.…”

“…Spatial "Walk-Off " in Lossy NRMs. Light incidents from free space onto a homogeneous, isotropic, lossy NRM, of permittivity ε r (ω) = ε + iε and permeability μ r (ω) = μ + iμ , were studied in detail [8]. The complex effective refractive index is then defined as n 2 (ω) = ε r (ω)μ r (ω) or n(ω) = n + in .…”

Optical refraction in silver: counterposition, negative phase velocity and orthogonal phase velocity

“…Within the past 10 years, interest in the reflection-refraction problem has been revived due to the development of certain metamaterials which support such exotic wave phenomena [7] as negative refraction [8,9], negative phase velocity (NPV) [10,11] and counterposition [12][13][14]. All three of these phenomena require consideration of the direction of energy flux, as quantified by the time-domain Poynting vector.…”

A plethora of negative-refraction phenomenons in relativistic and non-relativistic scenarios

“…However, some inconsistencies are apparent between reports over what exactly constitutes negative refraction. Sometimes what is actually being described is not negative refraction per se, but an associated phenomenon such as negative phase velocity, counterposition or negative deflection of energy flux [6,7]. While these phenomenons can-and often do-arise in conjunction with negative refraction, it is important to bear in mind that these are independent phenomenons which should be distinguished from negative refraction, especially so in complex materials and in relativistic scenarios.…”