Nonlinear Quantum Tunneling Effects in Nanoplasmonic Environments: Two-Photon Absorption and Harmonic Generation

Document Type

Article

Publication Date

6-2014

Publication Source

Journal of the Optical Society of America B

Abstract

We use a quantum mechanical approach to derive a set of linear and nonlinear quantum conductivity coefficients for metal–insulator–metal structures with nanometer sized gaps. The immediate proximity of metallic objects generates a tunneling AC current density that endows the gap region with additional linear and nonlinear coefficients that in turn trigger linear and nonlinear absorption, and second- and third-harmonic generation. For example, a vacuum gap approximately 0.8 nm thick displays an effective |��(2)|∼0.1  pm/V for adjacent objects composed of dissimilar metals and an effective |��(3)|∼10−20  m2/V2 for either similar or dissimilar metals, increasing exponentially for smaller gaps. Field localization inside the gap ensures that harmonic generation arising from the gap region overwhelms intrinsic metal second- and third-order nonlinearities.

Inclusive pages

A13-A19

ISBN/ISSN

0740-3224

Comments

Permission documentation is on file.

Publisher

Optical Society of America

Volume

31

Peer Reviewed

yes

Issue

6

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