Validation of THz absorption spectroscopy by a comparison with ps-TALIF measurements of atomic oxygen densities

This data set contains the data shown in the corresponding publication in Applied Physics Letters (https://doi.org/10.1063/5.0160303). This publication presents a benchmark of THz absorption spectroscopy against a more established method. Atomic oxygen densities were measured with THz absorption spectroscopy and compared to those obtained from picosecond (ps) two-photon absorption laser induced fluorescence (TALIF) measurements on the same capacitively coupled radio frequency oxygen discharge. Similar changes in the atomic oxygen density were observed with both diagnostics when varying the applied power (20–100 W) and the gas pressure (0.7–1.3 mbar). Quantitatively, the results are in good agreement as well, especially when considering the total margin of error of the two diagnostics. This shows that THz absorption spectroscopy is an accurate technique that can be reliably used for real-world applications to determine atomic oxygen densities in plasmas.