Figure 2
From: Dirac directional emission in anisotropic zero refractive index photonic crystals
Anisotropic zero-refractive-index in rhombic photonic crystal.
(a) Emission pattern from anisotropic zero-refractive-index photonic crystal with 72° rhombic lattice above Dirac frequency. (b) Output intensity ratio between the x and y directions, as a function of the permittivity of the anisotropic homogenous double near-zero (ADNZ) medium. The ADNZ material has the same effective refractive indices as (a) but different impedances/permittivity/permeability. (c) Emission pattern from the ADNZ material with the values of Zx = 2, Zy = 8, εz = 0.75 × 10−3, μx = 5.13 × 10−2, μy = 3.25 × 10−3, which has the same intensity ratio as (a). (d) Emission pattern from the rhombic photonic crystal below Dirac frequency to show the absence of anisotropic near-zero and directional emission.
