Nonlinear Metamaterial and Plasmonic Structures

Theory of nonlinear metamaterials [1] predicted that the hysteresis-type dependence of magnetic permeability on the field intensity may allow dramatic changes of the material properties. As the first step towards creating tunable nonlinear metamaterials we studied dynamic tunability of the magnetic resonance of a single nonlinear split-ring resonator [2] and revealed different tuning regimes of metamaterial. At higher powers the nonlinear response of the split-ring resonator becomes multi-valued, indicating that the memory effect can be potentially observed in nonlinear metamaterials. Recently, we fabricated the first tunable nonlinear magnetic [3] and nonlinear electric [4] metamaterials by placing varactors in each of the split-ring resonators or each of the electric resonators of the structure. We measured a very pronounced shift of the resonance, and observed a change of the transmission through the nonlinear metamaterial with split-ring resonators for different power levels [3]. We observe experimentally the intensity-suppressed and intensity-induced transparency, when the frequency of the incoming wave is at the left edge of the resonance. The achieved nonlinear suppression of the beam transmission is 20 dB for magnetic metamaterial [3], and almost 50dB for electric metamaterial [4].