Within this theoretical model, upon setting the initial and final frequencies of light to the same value, the mathematics describe the hyper Rayleigh scattering optical activity.
[2][3] The team investigated the hyper Rayleigh scattering (at the second harmonic generation frequency) from chiral nanohelices made of silver.
[8] Moreover, HRS OA is a parametric process: the initial and final quantum mechanical states of the excited electron are the same.
Soon after the first demonstration of hyper Rayleigh scattering optical activity in metal nanoparticles,[3] the effect was replicated in organic molecules, specifically aromatic oligoamide foldamers.
The first demonstration of hyper-Rayleigh scattering optical activity at the third harmonic was reported by Valev's team in 2021, from silver nanohelices.