Measurement of electric field strengths by fluorescence-dip Stark spectroscopy

We measured electric field strengths in the sheath region of a dc glow discharge in xenon by means of Stark spectroscopy. This laser spectroscopic technique is based on measuring Stark shifts of high-lying Rydberg levels due to external electric fields. We used a 2+1 photon excitation scheme with fluorescence dip detection, which made it possible to measure electric fields both in a plasma and in neutral gas. Quantification of the electric field strengths was done by comparing experimental Stark shifts with theoretical calculations