Various university groups and research institutes are taking advantage of the picometer resolution of the Hyperfine spectrometers to perform in-depth characterization of plasmas. One such team is that of Prof. Stafford, who has recently used the HN-8995-2 spectrometer to study the rotational-translational equilibrium in argon plasmas at atmospheric pressure1. Using optical emission spectroscopy, the researchers could measure the neutral gas temperature (a key parameter in plasma physics) with high precision. This was made possible by the <2 pm FWHM resolution of the Hyperfine spectrometer, which resulted in minimal instrument broadening. In another study, they characterized a low-pressure plasma using optical absorption spectroscopy2. Among other things, they showed that the measurements could not be achieved with an alternative standard-grating spectrometer despite the fact that it was also identified by the manufacturer as being high-resolution. The authors explain that “due to the <2 pm spectral resolution of the Hyperfine system, details on the absorption line intensity, position and width can be obtained with very high precision (…). The Hyperfine spectrometer is detecting light absorption where expected while the [standard grating] high-resolution spectrometer reveals no meaningful light absorption. This stunning result is ascribed to the distinct spectral resolution of the spectrometers (…).2

plasma spectroscopy setup.png

Figures obtained from [2]. Top: Schematic of the experimental setup, showing the Hyperfine spectrometer. Bottom left and right: Optical emission and absorption spectroscopy measurements of two 2p-1s transitions obtained with the “high-resolution” standard grating spectrometer and the Hyperfine spectrometer (bottom). Note that the wavelength scales differ by more than 2 orders of magnitude in the two graphs. It can be seen that the absorption features are detectable only with the HyperFine spectrometer, thanks to its <2 pm resolution.



[1] Labelle, Francis, et al. “On the rotational-translational equilibrium in non-thermal argon plasmas at atmospheric pressure.“ Plasma Sources Science and Technology (2021). Accepted manuscript.

[2] Durocher-Jean, Antoine, et al. "Ultra-high-resolution optical absorption spectroscopy of DC plasmas at low pressure using a supercontinuum laser combined with a laser line tunable filter and a Hyperfine spectrometer." Journal of Physics D: Applied Physics 54.8 (2020): 085204.