Fig. 7From: Focusing of THz waves with a microsize parabolic reflector made of graphene in the free spaceE-case: Focusing ability of graphene reflectors versus the frequency in the THz range for small-size reflector, d = 200 μm (a) and medium-size reflector, d = 1000 μm (b) Solid line (green): μ c = 0.3 eV, solid line (red): μ c = 0.5 eV, solid line (blue): μ c = 1 eV. Dashed line (black): PEC result. The other parameters are the same as in Fig. 2 Back to article page