Terahertz emission from surface-immobilized gold nanospheres

Electromagnetic wave emission based on optical rectification at terahertz (THz) wavelengths was observed from surface-immobilized gold nanospheres (SIGNs) above a gold surface. Although the excitation wavelength is off-resonant with the localized surface plasmons, the THz emission field was observed...

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Published inOptics letters Vol. 37; no. 19; p. 4053
Main Authors Kajikawa, Kotaro, Nagai, Yusuke, Uchiho, Yuichi, Ramakrishnan, Gopakumar, Kumar, Nishant, Ramanandan, Gopika K P, Planken, Paul C M
Format Journal Article
LanguageEnglish
Published United States 01.10.2012
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Summary:Electromagnetic wave emission based on optical rectification at terahertz (THz) wavelengths was observed from surface-immobilized gold nanospheres (SIGNs) above a gold surface. Although the excitation wavelength is off-resonant with the localized surface plasmons, the THz emission field was observed to be approximately 4.8 times greater than that from a percolated gold thin film of 10 nm thickness. A theoretical calculation predicts that the light electric field is enhanced in the SIGN system, even at off-resonance wavelengths. The observed THz field amplitude was quadratic with the illumination light field, suggesting that the THz generation is due to a second-order nonlinear optical process.
ISSN:1539-4794
DOI:10.1364/OL.37.004053