Solid-state high harmonic generation in common large bandgap substrate materials

Solid-state high harmonic generation (sHHG) spectroscopy is an emerging ultrafast technique for studying key material properties such as electronic structure at and away from equilibrium. sHHG anisotropy measurements, where sHHG spectra are recorded depending on the driving electric field relative to the crystal lattice, have become a powerful tool for studying crystal symmetries. Previous works on two-dimensional materials and other quantum materials have often used substrate-supported samples, assuming that all sHHG signals originate from the sample due to the relatively large bandgap of the substrate. While this assumption is generally reasonable, we show that some sHHG emissions from commonly used substrates can occur at moderate intensities of the sHHG driving field. In addition, we show that it is essential to consider not only the sHHG yield from a substrate but also its angular dependence relative to the material of interest. Specifically, in this work, the power-dependent and p..., , # Data Set: Solid-state high harmonic generation in common large bandage substrates

This data set contains all raw data and processed data for plotting shown in the paper that is open access here: [[https://pubs.acs.org/doi/full/10.1021/acs.jpca.4c04991](https://pubs.acs.org/doi/full/10.1021/acs.jpca.4c04991)].

# Description of the data and file structure

The data repository contains subfolders corresponding to each figure. Each subfolder contains data files (if data is shown in the figure). The primary parameters that are varied in a given experiment are represented in the raw-file name. The raw data files themselves are encoded in ASCII and contain two columns where the first column is the wavelength in nanometers and the second column is the number of counts. Each line represents a pixel on the spectrometer. The raw data files are otherwise unprocessed spectra as measured by the spectrometer. Processed data as plotted in the manuscript is also included with the contents described ...,