Polarization dependence of second harmonic generation from plasmonic nanoprism arrays

Abstract

The second order nonlinear optical response of gold nanoprisms arrays is investigated by means of second harmonic generation (SHG) experiments and simulations. The polarization dependence of the nonlinear response exhibits a 6-fold symmetry, attributed to the local field enhancement through the excitation of the surface plasmon resonances in bow-tie nanoantennas forming the arrays. Experiments show that for polarization of the input light producing excitation of the plasmonic resonances in the bow-tie nanoantennas, the SHG signal is enhanced; this despite the fact that the linear absorption spectrum is not dependent on polarization. The results are confirmed by electrodynamic simulations which demonstrate that SHG is also determined by the local field distribution in the nanoarrays. Moreover, the maximum of SHG intensity is observed at slightly off-resonance excitation, as implemented in the experiments, showing a close relation between the polarization dependence and the structure of the material, additionally revealing the importance of the presence of non-normal electric field components as under focused beam and oblique illumination.

The role of nonlocal response in second harmonic generation at metasurfaces with triangular metaatoms

“…Our argument was made for metasurfaces with just a few types of single particles in a unit cell. Extending this approach to previous discussions on other shapes or composite metaatoms [19][20][21][22][23][24][25][26] may help generalunderstanding of SHG in metaatoms.…”

Lithium niobate particles with a tunable diameter and porosity for optical second harmonic generation

“…61 The intensity of the SHG response depends on the relative orientation between the polarization of the incoming light and the second-order hyperpolarizability [c (2) ] of an NLO material. [62][63][64][65] The intensity of the SH signals varies as a function of the polarization of the incident light. 62 Lithium niobate is a uniaxial material with a rhombohedral crystal structure at room temperature and a single optical axis, the so-called c-axis.…”

A Toroidal‐Fano‐Resonant Metasurface with Optimal Cross‐Polarization Efficiency and Switchable Nonlinearity in the Near‐Infrared

“…The significance and complication of generating the polarization-dependent SHG are formerly reported in a honeycomb nanoprism array. [70] The STM as a facile exemplar is then expected to be a favorable candidate for generating robust nonlinear effects with the absence of the phase-matching condition due to its ability of strong field confinement, which is the main factor to produce the SHG. [71] A schematic of the SHG measurement setup is sketched in Figure 4a.…”