Title: Hot‐Electron‐Assisted Femtosecond All‐Optical Modulation in Plasmonics

Abstract

Abstract The optical Kerr nonlinearity of plasmonic metals provides enticing prospects for developing reconfigurable and ultracompact all‐optical modulators. In nanostructured metals, the coherent coupling of light energy to plasmon resonances creates a nonequilibrium electron distribution at an elevated electron temperature that gives rise to significant Kerr optical nonlinearities. Although enhanced nonlinear responses of metals facilitate the realization of efficient modulation devices, the intrinsically slow relaxation dynamics of the photoexcited carriers, primarily governed by electron–phonon interactions, impedes ultrafast all‐optical modulation. Here, femtosecond (≈190 fs) all‐optical modulation in plasmonic systems via the activation of relaxation pathways for hot electrons at the interface of metals and electron acceptor materials, following an on‐resonance excitation of subradiant lattice plasmon modes, is demonstrated. Both the relaxation kinetics and the optical nonlinearity can be actively tuned by leveraging the spectral response of the plasmonic design in the linear regime. The findings offer an opportunity to exploit hot‐electron‐induced nonlinearities for design of self‐contained, ultrafast, and low‐power all‐optical modulators based on plasmonic platforms.

Authors:

Taghinejad, Mohammad ^[1]; Taghinejad, Hossein ^[1]; Xu, Zihao ^[2]; Liu, Yawei ^[2]; Rodrigues, Sean P. ^[3]; Lee, Kyu‐Tae ^[1]; Lian, Tianquan ^[2]; Adibi, Ali ^[1]; Cai, Wenshan  ^[3]

• Search DOE PAGES for author "Cai, Wenshan"
• Search DOE PAGES for ORCID "0000-0002-6367-3857"

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+ Show Author Affiliations

1. School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA 30332 USA
2. Department of Chemistry Emory University Atlanta GA 30322 USA
3. School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA 30332 USA, School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332 USA

Publication Date:

Mon Jan 15 00:00:00 EST 2018

Sponsoring Org.:

USDOE

OSTI Identifier:

1416994

Grant/Contract Number:  

FG02‐12ER16347

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

Advanced Materials

Additional Journal Information:

Journal Name: Advanced Materials Journal Volume: 30 Journal Issue: 9; Journal ID: ISSN 0935-9648

Publisher:

Wiley Blackwell (John Wiley & Sons)

Country of Publication:

Germany

Language:

English