Thermomechanically Tunable Infrared Metamaterials Using Asymmetric Split-Ring Resonators

We demonstrate a nanoelectromechanical systems-based tunable infrared metamaterial formed with an array of Au/Si bilayer split-ring resonators having two asymmetric arms. The wider arm of the resonator is anchored on the substrate, while the thinner one is free to bend in vertical direction by varying temperature. The bending of the thin arm changes the air gap between the two arms, and thus modulates the optical resonance modes of the resonator. The presented tunable metamaterial has an ultra-small footprint size and provides a relatively large optical signal modulation at 3.6-μm wavelength.