On resolving the refractive index and the wave vector
On resolving the refractive index and the wave vector
The identification of the refractive index and the wave vector for general (possibly active) linear, isotropic, homogeneous, and nonspatially dispersive media is discussed. Correct conditions for negative refraction necessarily include the global properties of the permittivity and permeability functions ε=ε(ω) and μ=μ(ω). On the other hand, a necessary and sufficient …