Nonlinear plasmonic response in atomically thin metal films

Nanophotonics

Cox Joel D.¹  García de Abajo F. Javier²  Iyikanat Fadil²  Rodríguez Echarri Álvaro² 

[1] Center for Nano Optics, University of Southern Denmark, Campusvej 55, DK-5230Odense M, Denmark;ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860Castelldefels, Barcelona, Spain;

关键词: atomically thin films;    nonlinear optics;    nanophotonics;    plasmon polaritons;    scanning near-field optical microscopy (snom);   

DOI  :  10.1515/nanoph-2021-0422

来源: DOAJ

【 摘 要 】

Nanoscale nonlinear optics is limited by the inherently weak nonlinear response of conventional materials and the small light–matter interaction volumes available in nanostructures. Plasmonic excitations can alleviate these limitations through subwavelength light focusing, boosting optical near fields that drive the nonlinear response, but also suffering from large inelastic losses that are further aggravated by fabrication imperfections. Here, we theoretically explore the enhanced nonlinear response arising from extremely confined plasmon polaritons in few-atom-thick crystalline noble metal films. Our results are based on quantum-mechanical simulations of the nonlinear optical response in atomically thin metal films that incorporate crucial electronic band structure features associated with vertical quantum confinement, electron spill-out, and surface states. We predict an overall enhancement in plasmon-mediated nonlinear optical phenomena with decreasing film thickness, underscoring the importance of surface and electronic structure in the response of ultrathin metal films.

【 授权许可】

Unknown