Microelectromechanically reconfigurable interpixelated metamaterial for independent tuning of multiple resonances at terahertz spectral region

Tunability in metamaterials has added a new dimension to the functionality and application scope for light-matter interaction in the subwavelength regime. Microelectromechanical-systems-based microactuators have been reported as the most straightforward and efficient means of achieving tunable metamaterials, but so far can provide tunability of only a single electromagnetic property. This has greatly limited its usage in applications requiring either simultaneous or independent control of multiple parameters, such as linear polarization switching, actively controlled refractive indices, bandwidth tunable filters, and modulators. Here, we place an electrically isolated split ring resonator and an electrical split ring resonator in an interpixelated fashion to form a metamaterial super cell. The proposed metamaterial can be configured to have only magnetic resonance at 0.59 THz, only electrical resonance at 0.45 THz, or both magnetic and electrical resonances at 0.375 THz. The frequency at which magnetic and electrical resonance occurs is selectively changed by appropriately biasing the signaling lines of respective resonators. The proposed approach can be extended to have as many resonators as desired in a single complex metamolecule. Each of the unit cells is independently addressed and can be programmed, thereby enabling multiple functionalities using a single metamaterial in the terahertz spectral region. We believe that our proposed approach will enable the realization of a wide range of actively controlled EM properties, especially for active control of refractive indices and its potential applications. It will also aid in the realization of the ultimate form of tunable metamaterial, the "THz programmable metamaterial," which will likely be a disruptive technology in the near future. (C) 2015 Optical Society of America