Journal of Physics B Atomic Molecular and Optical Physics
Autler–Townes splitting in Rydberg atoms: transition dipole matrix element extraction and field efficiency analysis
Brian C Holloway, Gavin Michael Chase, Lee E. Harrell, David Hutchinson, William K. North, Tyler C. Catapano, Christian Francis Custodio, Simon Kirschenbaum, Michael Charles Speer, David O. Kashinski
Abstract
Abstract We report the observation and quantitative analysis of Autler–Townes splitting in rubidium atoms excited to Rydberg states using a four-level ladder-type electromagnetically induced transparency (EIT) scheme and resonant radio-frequency (RF) fields. By fitting the EIT spectra to Voigt profiles and calibrating the frequency axis with a semi-empirical Rydberg–Ritz model, we extracted transition dipole matrix elements (TDMEs) for the n D 5 / 2 → ( n + 1 ) P 3 / 2 transitions across five principal quantum numbers: n = 53, 55, 68, 75, and 85. Comparison with theoretical predictions revealed systematic deviations in the Rabi frequencies, attributed to RF delivery inefficiencies and standing-wave enhancement within the vapor cell. To address these effects, we developed two complementary approaches: an empirical quartic fit to measured efficiencies and a physics-based model, capturing both transverse radial variation and dominant longitudinal interference along the cell axis. These models explain the observed scaling behavior, predict an efficiency peak near n ≈ 60, and reduce TDME discrepancies to less than 5% at the validation point. Our analysis highlights the influence of spatial field distribution and cell geometry on precision atom–field interaction measurements and establishes a robust experimental framework for TDME extraction in ladder-type EIT systems.