Open AccessNear-UV-enhanced broad-band large third-order optical nonlinearity in aluminum nanorod array film with sub-10 nm gaps
Author(s) -
Zongwei Ma,
Cheng Chi,
Ying Yu,
Zhou Zhong,
Lei Yao,
ZhangKai Zhou,
Xia Wang,
Yibo Han,
Junbo Han
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.005387
Subject(s) - materials science , nanorod , plasmon , optoelectronics , wavelength , optics , nanostructure , figure of merit , electric field , nonlinear optics , ultraviolet , nanotechnology , laser , physics , quantum mechanics
Plasmonic nanostructures with sub-10 nm gaps possess intense electric field enhancements, leading to their high reputation for exploring various functional applications at nanoscale. Till now, although large amounts of efforts have been devoted into investigation of such structures, few works were emphased on the nonlinear optical properties in near-ultraviolet (UV) region. Here, by combining sputtering technique and an optimized anodic aluminum oxide (AAO) template growing method, we obtain aluminum (Al) nanorod array film (NRAF) with average rod diameter and gap size of 50 and 7 nm, respectively. The Al-NRAF exhibits large third-order optical nonlinear susceptibility (χ (3) ) and high figure of merit (χ (3) /α) over a broad wavelength range from 360 to 900 nm, and reaches their maximums at the shortest measured wavelength. In addition, comparisons with Au-NRAF and Ag-NRAF samples further confirm that Al-NRAF has better nonlinear optical properties in the blue and near-UV wavelength regions. These results indicate that Al nanostructures are promising candidates for nonlinear plasmonic applications at blue and near-UV wavelengths.