Figure 3. Dispersion of five strongest multipoles contributing to the metamaterial response.

(a) Dispersion of radiated power in the case of threshold gain. (b) Dispersion of radiated power in the case of amplification maximum. Color map and black streamline show the magnetic energy in logarithm scale and the magnetic field distribution at the toroidal resonances for different values of gain coefficients. The inset of (b) presents the enlarged dispersion of radiated power around toroidal resonance.