Electromagnetic resonance strength in metamaterials

Besides the resonance frequency, the resonance strength is another key optical characteristic for metamaterials. In the present work, a theoretical model for the resonance strength is proposed, which has been numerically and experimentally verified by the fundamental and high-order resonances of metamaterials. Results show that the resonance strength is determined by the electric potential difference induced by incident waves and could be efficiently tuned by changing the polarized state of incident waves or the shape of resonant units. Interestingly, the fundamental resonance could be completely suppressed, and the maximum magnitude of the high-order resonance strength for a metamaterial also can be predicted with the model. Further simulated results indicated that, among different-shaped metamaterials, I-shaped metamaterials as a simpler structure can have a stronger resonance strength in both of the low-order and high-order resonances. It may inspire the design of metasurfaces based high-order resonances and may offer a powerful strategy for further optimizations of the performance of metamaterial-based devices.