Nonlinear Optical Nano-imaging of Graphene
ORAL
Abstract
Nonlinear optical response offers a powerful tool for investigating a wide range of phenomena in physics, chemistry, and biology and provides a basis for future photonic and optoelectronic applications. Nonlinear optics of graphene is particularly interesting due to the unique Dirac-cone band structure, with the associated strong nonlinear response over a broad spectral range. Here, we apply the adiabatic plasmonic nanofocusing technique to study the mechanism and nanoscale spatial heterogeneity of the nonlinear optical response of graphene. We generate strong four-wave mixing (FWM) signal in monolayer and few-layer graphene with compressed surface plasmon polaritons (SPPs) at a Au nano-tip apex and investigate its heterogeneity by nonlinear imaging with nanoscale spatial resolution. We find a pronounced enhancement of the graphene FWM response at crystal edges associated with the formation of a tip-edge resonant cavity and study its mechanism and properties by spectral tuning and electrostatic gating. Our results reveal highly localized and plasmon-enhanced nonlinear optical interactions in graphene and suggest exciting possibilities of graphene-plasmon-mediated nonlinearities, with applications in photonic circuits, all-optical information processing, and quantum optics.
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Presenters
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Tao Jiang
- Department of Physics, Department of Chemistry, JILA, and Center for Experiments on Quantum Materials, Univ of Colorado - Boulder
- Fudan University
- Physics, Chemistry, and JILA, Univ of Colorado