Figure 2
From: Broadband absorption using all-graphene grating-coupled nanoparticles on a reflector
The extinction efficiency of (a) dipole and (b) quadrupole modes for hollow (ε1 = 1) graphene-wrapped spherical particle with various radii R. The optical parameters of graphene cover with the surface conductivity σ are τ = 32.9 fs, and μc1 = 0.95 eV. The extinction efficiency is the extinction cross-section obtained by the modified Mie-Lorenz theory, normalized to the geometrical cross-section52.
