Figure 7.

(a) Absorptions with different polarizations; Fermi energy levels (μ_c) of 0.2 eV, 0.5 eV, and 0.8 eV; and $\tau =\frac{\mu {\mu }_c}{e{v}_{\mathrm{F}}^2}$. (b) Central frequencies with consecutive Fermi energy levels from 0.75 eV to 0.85 eV.