Dataset for "Chiroptical Second-Harmonic Tyndall from Silicon Nanohelices"

Data collection method:

Experimental data was recorded directly from the SR500 photon counter to a .txt file using LabView 2016 with a counting time of 5s. Data was imported into OriginPro2021 and organised. Medians were taken of the data and the resulting averages arranged to their corresponding scattering types (right angle, forward, RCP, LCP light) A mean of all data corresponding to a reference data for a given power was taken, and plotted as a function of measured power to give a curve. The averages for the second harmonic intensity is fitted against this curve to give an accurate average power ------------------------------------------------------------------------ Simulated data collected using Lumerical FDTD solver. For linear simulations, we extracted scattering and absorption cross sections from 6 power monitors surrounding the source and nanoparticle respectively. For the absorption 3D distribution, linear simulations provided absorption density in the nanoparticle which was then plotted in Matlab. For multipole solver, electromagnetic fields were extracted from 6 field profile monitors around the nanoparticle and from the refractive index profile monitor. These fields were then imported into MENP solver in MatLab (see link at end). Nonlinear simulations used chi 2 medium for the nanohelix and continuous wave normalisation was turned off. A high intensity fundamental field excited the nanohelix and near fields at second harmonic wavelength were measured by field profile monitors.

Technical details and requirements:

Raw data files can be accessed using notepad or other program that can open .txt files. Files containing the graphs and processed data require OriginPro. Software for simulations: Lumerical 2022, MatLab 2022b

Additional information:

Experimental data: Data files for a given measurement are placed in a named folder describing the measurement. (eg Si-pos power 750 nm refers to power dependence measurements for the Si (+) helices performed at an incident wavelength of 750 nm) ----------------------------------------- Simulation: Files for each simulation are placed in folders describing the type of simulation (eg multipole, SHS). Individual files are named with the wavelength, nanohelix orientation and circular polarisation used.

Methodology link: