Sautter, JurgenXu, LeiMiroshnichenko, AndreyLysevych, MykhayloVolkovskaya, IrinaSmirnova, DariaCamacho Morales, Maria (Rocio)Kamali, KhosroKarouta, FouadVora, VallabhbhaiTan, Hark HoeKauranen, MarttiStaude, IsabelleJagadish, ChennupatiNeshev, DragomirRahmani, Mohsen2020-03-031530-6984http://hdl.handle.net/1885/202006Second-harmonic generation (SHG) in resonant dielectric Mie-scattering nanoparticles has been hailed as a powerful platform for nonlinear light sources. While bulk-SHG is suppressed in elemental semiconductors, for example, silicon and germanium due to their centrosymmetry, the group of zincblende III–V compound semiconductors, especially (100)-grown AlGaAs and GaAs, have recently been presented as promising alternatives. However, major obstacles to push the technology toward practical applications are the limited control over directionality of the SH emission and especially zero forward/backward radiation, resulting from the peculiar nature of the second-order nonlinear susceptibility of this otherwise highly promising group of semiconductors. Furthermore, the generated SH signal for (100)-GaAs nanoparticles depends strongly on the polarization of the pump. In this work, we provide both theoretically and experimentally a solution to these problems by presenting the first SHG nanoantennas made from (111)-GaAs embedded in a low index material. These nanoantennas show superior forward directionality compared to their (100)-counterparts. Most importantly, based on the special symmetry of the crystalline structure, it is possible to manipulate the SHG radiation pattern of the nanoantennas by changing the pump polarization without affecting the linear properties and the total nonlinear conversion efficiency, hence paving the way for efficient and flexible nonlinear beam-shaping devices.The authors acknowledge the financial support by the Australian Research Council and the use of the Australian National Fabrication Facility (ANFF), the ACT Node. M.R. sincerely appreciates funding from ARC Discovery Early Career Research Fellowship (DE170100250) and The Australian Nanotechnology Network. J.D.S. and I.S. gratefully acknowledge the financial support by the German Research Foundation (STA 1426/2-1). The work of A.E.M. was supported by a UNSW Scientia Fellowship. I.V. and D.S. acknowledge financial support by the Russian Foundation for Basic Research (Grants 18-02-00381, 19-02-00261). R.C.-M. acknowledges a grant from Consejo Nacional de Ciencia y Tecnologıa (CONACYT), Mexico. The work of M.K. was ́supported by the Flagship of Photonics Research and Innovation (Academy of Finland 320165) and by Tampere University.7 pagesapplication/pdfen-AU© 2019 American Chemical SocietyDielectric nanoantennas, second harmonic generation, III−V semiconductors, directional emission, Mie resonance, multipolar interference2019-05-2810.1021/acs.nanolett.9b011122019-11-25