Abstract:
We derive an approach to determine the causal direction of wavevectors of modes in optical
metamaterials, which, in turn, determines signs of refractive index and impedance as a function of
real and imaginary parts of dielectric permittivity and magnetic permeability. We use the developed
technique to demonstrate that the interplay between resonant response of constituents of
metamaterials can be used to achieve efficient dispersion management. Finally, we demonstrate
broadband dispersionless index and impedance matching in active nanowire-based negative index
materials. Our work has a potential to open new practical applications of negative index composites
for broadband lensing, imaging, and pulse routing.
