Tunable second harmonic generation by an all-dielectric diffractive metasurface embedded in liquid crystals
Year: 2022
Authors: Rocco D., Zilli A., Ferraro A., Borne A., Vinel V., Leo G., Lemaitre A., Zucchetti C., Celebrano M., Caputo R., De Angelis C., Finazzi M.
Autors Affiliation: Department of Information Engineering, University of Brescia, via Branze 38, Brescia 25123, Italy; National Institute of Optics (INO), via Branze 45, 25123 Brescia, Italy; Department of Physics, Politecnico di Milano, Piazza Leonardo Da Vinci 32, Milano 20133, Italy; Department of Physics & CNR-NANOTEC, University of Calabria, via P. Bucci, Cubo 31 C, Rende 87036, Italy; Universit?e de Paris, CNRS, LaboratoireMat?eriaux et Ph?enom?enes Quantiques, 75013 Paris, France; University Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France; Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, People?s Republic of China
Abstract: We experimentally demonstrate the possibility to modulate the second harmonic (SH) power emitted by nonlinear AlGaAs metasurfaces embedded in a liquid crystal (LC) matrix. This result is obtained by changing the relative in-plane orientation between the LC director and the linear polarization of the light at the excitation wavelength. According to numerical simulations, second-harmonic is efficiently radiated by the metasurfaces thanks to the sizeable second-order susceptibility of the material and the resonant excitation of either electric or magnetic dipole field distributions inside each meta-atom at the illuminating fundamental wavelength. This resonant behavior strongly depends on the geometric parameters, the crystallographic orientation, and the anisotropy of the metasurface, which can be optimized to modulate the emitted SH power by about one order of magnitude. The devised hybrid platforms are therefore appealing in view of enabling the electrical control of flat nonlinear optical devices.
Journal/Review: NEW JOURNAL OF PHYSICS
Volume: 24 (4) Pages from: 045002-1 to: 045002-8
More Information: The authors acknowledge financial support from the European Union´s Horizon 2020 Research and Innovation program under the Grant Agreement No. 899673 (METAFAST) and from the Italian Ministry of University and Research through the PRIN Project NOMEN (2017MP7F8F). This work was partly supported by the French RENATECH network. AF and RC would like to acknowledge the financial support ´DEMETRA-Sviluppo di tecnologie di materiali edi tracciabilita per la sicurezza e la qualita dei cibi´ (PON ARS01 00401) funded by Piano Operativo Nazionale-Ministero dell´Universita e della Ricerca.KeyWords: second harmonic generation; nonlinear optics; metasurfaces; liquid crystals; nanophotonicsDOI: 10.1088/1367-2630/ac61d2