Near-Zero-Refractive-Index Structure at Optical Frequencies

Figure 7

(a) The real part of the effective refractive index, 𝑛, versus the frequency for TE_𝑚, 𝑚=0,1,2,3. (b) The imaginary part of the effective refractive index (the extinction coefficient), 𝛾, versus the frequency for same set of modes. Note that 𝑚=0 (dash), 𝑚=1 (dot-dashed), 𝑚=2 (dotted), and 𝑚=3 (solid).

(a)

(b)