Enhanced second-harmonic generation with structured light in AlGaAs nanoparticles governed by magnetic response
E. V. Melik-Gaykazyan+*, K. L. Koshelev*×, J.-H. Choi°, S. S. Kruk*, H.-G. Park°, A. A. Fedyanin+, Y. S. Kivshar*
+Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
*Nonlinear Physics Centre, Australian National University, ACT 2601, Canberra, Australia
× Information Technologies, Mechanics and Optics University, 197101 St. Petersburg, Russia
°Department of Physics, Korea University, 02841 Seoul, Republic of Korea
Abstract
We employ structured light for the second-harmonic generation from
subwavelength AlGaAs nanoparticles that support both electric and magnetic
multipolar Mie resonances. The vectorial structure of the pump beam allows
addressing selectively Mie-resonant modes and control the strength of the
generated nonlinear fields. We observe experimentally the enhancement of the
second-harmonic generation for the azimuthally polarized vector beams near
magnetic dipole resonance, and match our observations with the numerical
decomposion of
the Mie-type multipoles for the fundamental and generated second-harmonic
fields.