Second Harmonic Generation from Phase-Engineered Metasurfaces of Nanoprisms

Abstract

Metasurfaces of gold (Au) nanoparticles on a SiO2-Si substrate were fabricated for the enhancement of second harmonic generation (SHG) using electron beam lithography and lift-off. Triangular Au nanoprisms which are non-centro-symmetric and support second-order nonlinearity were examined for SHG. The thickness of the SiO2 spacer is shown to be an effective parameter to tune for maximising SHG. Electrical field enhancement at the fundamental wavelength was shown to define the SHG intensity. Numerical modeling of light enhancement was verified by experimental measurements of SHG and reflectivity spectra at the normal incidence. At the plasmonic resonance, SHG is enhanced up to ∼3.5 × 103 times for the optimised conditions.

Fabrication and evaluation of rib-waveguide-type wavelength conversion devices using GaN-QPM crystals

“…m QPM = 3), as the power of the incident light increased, the SHG peak position shifted to the low angle side; this may be attributable to the increased substrate temperature under irradiation with a high-power laser. Mochizuki et al 40) reported such a phenomenon in the same measurement system. The phase-matching condition was considered to be changed by the changed refractive index caused by the increased substrate temperature.…”

Second Harmonic Generation From Phase-Engineered Metasurfaces of Nanoprisms

“…for the most efficient SHG and a good match between theoretical estimates and experimentally measured R values was observed at the peak of SHG. It could be envisaged that by using different 2D and 3D nanofabrication techniques including direct laser writing [23][24][25][26] it should be possible to inscribe non-centrosymmetric patterns into the interface or fill by NLO polymers rendering such meta-surfaces/materials as efficient SHG materials [27]. The use of reflective plasmonic non-centrosymmetric patterns are very promising for nanoscale engineering of SHG [28,29].…”

Second harmonic generation from metal nanoparticle dimer: an analytical approach in dipole approximation

“…In a large number of theoretical and experimental studies regarding to the plasmonics of metallic nanostructures including spherical MNPs, it is proven that the interaction of adjacent elements in a dimer and array of nanostructures can lead to the significant improvement of the SHG via the enhancement of local fields [17][18][19][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. Formation of plasmonic hot spot in the interaction of laser with MNPs inside a dielectric also can lead to the enhancement of SHG which can be used for the monitoring of growth of MNPs and some other dynamic aspects of chemical and biophysical processes [48][49][50][51][52][53][54][55].…”