title: Electrifying photonic metamaterials for tunable nonlinear optics.
abstract: Metamaterials have not only enabled unprecedented flexibility in producing unconventional optical properties that are not found in nature, they have also provided exciting potential to create customized nonlinear media with high-order properties correlated to linear behaviour. Two particularly compelling directions are active metamaterials, whose optical properties can be purposely tailored by external stimuli in a reversible manner, and nonlinear metamaterials, which enable intensity-dependent frequency conversion of light waves. Here, by exploring the interaction of these two directions, we leverage the electrical and optical functions simultaneously supported in nanostructured metals and demonstrate electrically controlled nonlinear optical processes from a metamaterial. Both second harmonic generation and optical rectification, enhanced by the resonance behaviour in the metamaterial absorber, are modulated externally with applied voltage signals. Our results reveal an opportunity to exploit optical metamaterials as self-contained, dynamic electro-optic systems with intrinsically embedded electrical functions and optical nonlinearities.
authors.affiliation: 1] School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA [2].
authors.forename: Lei
authors.initials: L
authors.lastname: Kang
authors.affiliation: 1] School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA [2].
authors.forename: Yonghao
authors.initials: Y
authors.lastname: Cui
authors.affiliation: 1] School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA [2].
authors.forename: Shoufeng
authors.initials: S
authors.lastname: Lan
authors.affiliation: 1] School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA [2] School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Rodrigues
authors.affiliation: Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Brongersma
authors.affiliation: 1] School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA [2] School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Wenshan
authors.initials: W
authors.lastname: Cai