(a) Refraction of wave fronts at an interface between vacuum and a NIM. (b) Refraction of the group velocity at an interface between vacuum and a NIM.Reuse & Permissions
Figure 2
(a) In an isotropic medium two waves of different frequencies reveal the group velocity through their interference pattern provided that we choose the wave vectors of the two waves to be parallel. (b) Two waves of different frequencies and nonparallel wave vectors result in an interference pattern moving with velocity unrelated to the group velocity.Reuse & Permissions
Figure 3
A series of pulses changing shape as they undergo negative refraction.Reuse & Permissions