Enhanced second-harmonic generation from L-shaped AlGaAs nanoantennasJOSA B
- Tao Zeng, Ling Guo, Long Xu, and Tiancheng Han
- received 10/23/2019; accepted 01/15/2020; posted 01/17/2020; Doc. ID 356071
- Abstract: Nanostructured materials offer many advantages over bulk materials in nonlinear optical phenomena. For example, the subwavelength scale allows the neglect of phase matching issues. Also, the ability to control tight confinement and large resonant enhancement of electromagnetic fields results in higher nonlinear frequency conversion efficiencies than bulk materials. Compared with plasmonic nanostructures, high-index dielectric nanoparticles render larger mode volumes and show great promise for enhanced nonlinear optical processes. In this work, we present resonantly enhanced second-harmonic generation (SHG) from L-shaped AlGaAs nanoantennas. By tuning the nanostructure thickness, arm length and width, the overlap of resonances at fundamental and second harmonic wavelength can be realized with any pump wavelength in a broad near-infrared spectral region. We predict SHG efficiency exceeding 4 × 10-3 with pump intensity of 1 GW/cm2 at two representative pump wavelengths of 1675 nm and 1800 nm. Our findings are valuable in the applications involving all-dielectric nanoantennas, such as efficient sensing and single biomolecule tracking microscopy.