Figure 3 | Polarization and symmetry analyses of SHG. (IMAGE)
Caption
Figure 3 | Polarization and symmetry analyses of SHG. Schematic illustrations of a symmetric and d asymmetry dimer-on-film geometries. b Under MD resonant excitation, Lorentz-term-driven nonlinear polarization is proportional to the cross product of the electric and magnetic fields, and x-polarized SHG exhibits a two-lobed pattern. c In contrast, y-polarized SHG is dominated by Coulomb and convective terms and displays a typical quadrupolar pattern. e Inspired by prior work on electromagnetically symmetry-breaking SHG enhancement (Nat. Commun. 2021, 12, 4326), the mirror symmetry of the dimer in the horizontal direction is broken by using spheres of different diameters (100 nm and 50 nm) to further explore multipolar interactions. Indeed, the mirror-symmetry-broken structure enhances electric dipole contributions and further improves field overlap, significantly increasing SHG emission: x-polarized SHG retains the two-lobed feature, with small rotations of the lobes indicating interactions between MD and ED; f for y-polarized detection, the quadrupole pattern rotates, reflecting coupling among multipolar components.
Credit
Wang, Y., Razdolski, I. et al.
Usage Restrictions
Credit must be given to the creator.
License
CC BY