All-Optical Control of a Single Plasmonic Nanoantenna-ITO Hybrid

SEPnet and the Department of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom.
Nano Letters (Impact Factor: 13.59). 06/2011; 11(6):2457-63. DOI: 10.1021/nl200901w
Source: PubMed


We demonstrate experimentally picosecond all-optical control of a single plasmonic nanoantenna embedded in indium tin oxide (ITO). We identify a picosecond response of the antenna-ITO hybrid system, which is distinctly different from transient bleaching observed for gold antennas on a nonconducting SiO(2) substrate. Our experimental results can be explained by the large free-carrier nonlinearity of ITO, which is enhanced by plasmon-induced hot-electron injection from the gold nanoantenna into the conductive oxide. The combination of tunable antenna-ITO hybrids with nanoscale plasmonic energy transfer mechanisms, as demonstrated here, opens a path for new ultrafast devices to produce nanoplasmonic switching and control.

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    • "discussed previously related to a much slower, thermo-optic nonlinearity of ITO [33], where we found a spectral response closely resembling the shape and sign change found in Fig. 3g. Other studies have identified carrier density modulation as the governing nonlinearity of ITO under UV laser excitation [34]. "
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