Dataset for "Chiroptical third-harmonic scattering spectroscopy of Ag and Si nanohelices"

This dataset provides broadband third‑harmonic scattering (THS) spectra of chiral Ag and Si nanohelices under tunable near‑infrared excitation across multiple discrete wavelengths. For both forward and right‑angle scattering geometries, the dataset includes nonlinear ellipticity values and power‑dependent measurements confirming third‑order nonlinear scaling. Ag nanohelices exhibit enantiomer‑dependent mirror‑image ellipticity, whereas Si nanohelices show geometry‑specific spectral signatures. The dataset also contains SEM images of the samples and linear circular dichroism (CD) characterization for both material systems.