Self-tuning of second-harmonic generation in GaAs nanowires enabled by nonlinear absorption
Authors: Carletti L., de Ceglia D., Vincenti MA., De Angelis C.
Autors Affiliation: Univ Padua, Dept Informat Engn, I-35131 Padua, Italy; Univ Brescia, Dept Informat Engn, I-25123 Brescia, Italy; CNR, Natl Inst Opt INO, I-25123 Brescia, Italy
Abstract: We investigate the effects of nonlinear absorption of the pump beam on second-harmonic generation in GaAs nanowires. Our model includes nonlinear absorption of the pump and allows obtaining a self-consistent solution of the nonlinear Maxwell equations. First, we observe that SHG conversion efficiency can be limited from two-photon absorption and generated free-carriers depending on the pump intensity. Second, we show a method to modulate the SHG response by varying the pump beam intensity. We find that varying the pump intensity from 1 GW/cm(2) up to 15 GW/cm(2) can red-shift the SH peak wavelength up to 5 nm and modulate the conversion efficiency at a fixed pump wavelength up to 60%. Our results enable new applications of dielectric nanoresonators for nonlinear applications such as harmonic generation, optical switching, and all-optical ultrafast modulation. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Journal/Review: OPTICS EXPRESS
Volume: 27 (22) Pages from: 32480 to: 32489