Vertical Second Harmonic Generation in Asymmetric Dielectric Nanoantennas

• Published in: IEEE photonics journal Vol. 12; no. 3; pp. 1 - 7
• Main Authors: Rocco, Davide, Gigli, Carlo, Carletti, Luca, Marino, Giuseppe, Vincenti, Maria Antonietta, Leo, Giuseppe, De Angelis, Costantino
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.06.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum gallium arsenides; Antenna radiation patterns; Broken symmetry; Design optimization; Dielectrics; Epitaxial growth; Gratings; Harmonic radiation; Nanoantennas; Nonlinear optics; Nonlinear optics devices; Numerical aperture; Optical harmonic generation; optical resonator; Optical resonators; Second harmonic generation; Substrates; Tensors; Zincblende
• ISSN: 1943-0655; 1943-0655; 1943-0647
• DOI: 10.1109/JPHOT.2020.2988502

High-permittivity III-V semiconductor nanocavities have shown huge potential for enhanced nonlinear light-matter interactions at the nanoscale. In particular, Second Harmonic (SH) generation in AlGaAs nanoantennas can be extremely efficient; however, vertical emission is difficult to achieve, due to the zincblende χ (2) tensor and epitaxially growth on (100) substrates. Here, we demonstrate that we can shape the second harmonic radiation pattern from a single AlGaAs nanostructure by exploiting a geometrical symmetry breaking optimization approach. The optimized design allows to redirect the SH signal toward the normal direction and to increase the SH power collection efficiency by 2 orders of magnitude in a small numerical aperture of 0.1 with respect to the symmetrical counterpart structure.