Rydberg electromagnetically induced transparency of $^{85}$Rb vapor in Ar, Ne and N$_2$ gases

TL;DR

This study investigates how inert gases like argon, neon, and nitrogen affect Rydberg electromagnetically induced transparency in rubidium vapor, providing insights for using Rydberg-EIT as a non-intrusive optical diagnostic tool.

Contribution

It presents experimental measurements of frequency shifts and line broadening in Rydberg-EIT due to inert gases, supported by a pseudo-potential model including electron-atom interactions.

Findings

Inert gases cause measurable shifts and broadening of EIT spectra.

Results align with a model considering s-wave scattering and polarization effects.

Findings support Rydberg-EIT as a diagnostic in low-pressure plasmas.

Abstract

An experimental study on Rydberg electromagnetically induced transparency (EIT) in rubidium (Rb) vapor cells containing inert gases at pressures $\le 5$ Torr is reported. Using an inert-gas-free Rb vapor cell as a reference, we measure frequency shift and line broadening of the EIT spectra in Rb vapor cells with argon, neon or nitrogen gases at pressures ranging from a few mTorr to 5 Torr. The results qualitatively agree with a pseudo-potential model that includes $s$-wave scattering between the Rydberg electron and the inert-gas atoms, and the effect of polarization of the inert-gas atoms by the Rydberg atoms. Our results are important for establishing Rydberg-EIT as an all-optical and non-intrusive spectroscopic probe for field diagnostics in low-pressure radio-frequency discharges.