Here we report the experimental observation of circular dichroism in the second-harmonic field (800-400 nm conversion) generated by self-organized gold nanowire arrays with subwavelength periodicity (160 nm). Such circular dichroism, raised by a nonlinear optical extrinsic chirality, is the evident signature of the sample morphology. It arises from the curvature of the self-assembled wires, producing a lack of symmetry at oblique incidence. The results were compared, both in the optical linear and nonlinear regime, with a reference sample composed of straight wires. Despite the weak extrinsic optical chirality of our samples (not observable by our optical linear measurements), high visibility (more than 50%) was obtained in the second-harmonic generated field.
Circular Dichroism in the Optical Second-Harmonic Emission of Curved Gold Metal Nanowires / Belardini, Alessandro; Larciprete, Maria Cristina; Centini, Marco; Fazio, Eugenio; Sibilia, Concetta; D., Chiappe; C., Martella; A., Toma; M., Giordano; F., Buatier De Mongeot. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 107:25(2011), pp. 257401-1-257401-5. [10.1103/physrevlett.107.257401]
Circular Dichroism in the Optical Second-Harmonic Emission of Curved Gold Metal Nanowires
BELARDINI, ALESSANDRO;LARCIPRETE, Maria Cristina;CENTINI, MARCO;FAZIO, Eugenio;SIBILIA, Concetta;
2011
Abstract
Here we report the experimental observation of circular dichroism in the second-harmonic field (800-400 nm conversion) generated by self-organized gold nanowire arrays with subwavelength periodicity (160 nm). Such circular dichroism, raised by a nonlinear optical extrinsic chirality, is the evident signature of the sample morphology. It arises from the curvature of the self-assembled wires, producing a lack of symmetry at oblique incidence. The results were compared, both in the optical linear and nonlinear regime, with a reference sample composed of straight wires. Despite the weak extrinsic optical chirality of our samples (not observable by our optical linear measurements), high visibility (more than 50%) was obtained in the second-harmonic generated field.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.