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Proceedings Paper • Open Access • new

Second harmonic generation on self-assembled GaAs/Au nanowires with thickness gradient
Author(s): A. Belardini; G. Leahu; M. Centini; R. Li Voti; E. Fazio; C. Sibilia; D. Repetto; F. Buatier de Mongeot

Paper Abstract

Here we investigated the SH generation at the wavelength of 400 nm (pump laser at 800 nm, 120 fs pulses) of a “metasurface” composed by an alternation of GaAs nano-grooves and Au nanowires capping portions of flat GaAs. The nano-grooves depth and the Au nanowires thickness gradually vary across the sample. The samples are obtained by ion bombardment at glancing angle on a 150 nm Au mask evaporated on a GaAs plane wafer. The irradiation process erodes anisotropically the surface, creating Au nanowires and, at high ion dose, grooves in the underlying GaAs substrate (pattern transfer). The SHG measurements are performed for different pump linear polarization angle at different positions on the “metasurface” in order to explore the regions with optimal conditions for SHG efficiency. The pump polarization angle is scanned by rotating a half-wave retarder plate. While the output SH signal in reflection is analyzed by setting the polarizer in ‘s’ or ‘p’ configuration in front of the detector. The best polarization condition for SHG is obtained in the configuration where the pump and second harmonic fields are both ‘p’ polarized, and the experiments show a SH polarization dependence of the same symmetry of bulk GaAs. Thus, the presence of gold contributes only as field localization effect, but do not contributes directly as SH generator.

Paper Details

Date Published: 30 May 2017
PDF: 10 pages
Proc. SPIE 10228, Nonlinear Optics and Applications X, 102280L (30 May 2017); doi: 10.1117/12.2268698
Show Author Affiliations
A. Belardini, Sapienza Univ. di Roma (Italy)
G. Leahu, Sapienza Univ. di Roma (Italy)
M. Centini, Sapienza Univ. di Roma (Italy)
R. Li Voti, Sapienza Univ. di Roma (Italy)
E. Fazio, Sapienza Univ. di Roma (Italy)
C. Sibilia, Sapienza Univ. di Roma (Italy)
D. Repetto, Univ. degli Studi di Genova (Italy)
F. Buatier de Mongeot, Univ. degli Studi di Genova (Italy)


Published in SPIE Proceedings Vol. 10228:
Nonlinear Optics and Applications X
Mario Bertolotti; Joseph W. Haus; Alexei M. Zheltikov, Editor(s)

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