Tuning harmonics with electronics: Voltage controlled nonlinear optics in nanostructured metals (Conference Presentation)

Abstract

Metallic nanostructures have offered not only the exciting opportunity to manipulate light waves in unconventional manners, but also the exciting potential to create customized nonlinear media with tailored high-order effects. Two particularly compelling directions of current interests are active plasmonics, where the optical properties can be purposely manipulated by external stimuli, and nonlinear plasmonics, which enable intensity-dependent frequency conversion of light. 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 processes from plasmonic metamaterials. We show that a variety of nonlinear optical phenomena, including the wave mixing and the optical rectification, can be purposely modulated by applied voltage signals. In addition, electrically-induced and voltage-controlled nonlinear effects facilitate us to demonstrate the backward phase matching in a negative index material, a long standing prediction in nonlinear metamaterials. Other results to be covered in this talk include photon-drag effect in plasmonic metamaterials and ion-assisted nonlinear effects from plasmonic crystals in electrolytes. Our results reveal a grand opportunity to exploit plasmonic metamaterials as self-contained, dynamic electrooptic systems with intrinsically embedded electrical functions and optical nonlinearities for signal generation, information processing, and biochemical sensing. Reference: L. Kang, Y. Cui, S. Lan, S. P. Rodrigues, M. L. Brongersma, and W. Cai, Nature Communications, 5, 4680 (2014). S. P. Rodrigues and W.Cai, Nature Nanotechnology, 10, 387 (2015). S. Lan, L. Kang, D. T. Schoen, S. P. Rodrigues, Y. Cui, M. L. Brongersma, and W. Cai, Nature Materials, 14, 807 (2015). S. Lan, S. P. Rodrigues, Y. Cui, L. Kang, and W. Cai, Nano Letters, 16, 5074 (2016).