Modeling Line Broadening and Distortion Due to Spatially Non-Uniform Fields in Rydberg Electrometry

Abstract

We present a model for calculating broadened Autler-Townes spectra when probing ac electric field magnitudes by use of Rydberg atom electromagnetically-induced transparency. This model approximates the atom vapor as a multi-layered media and uses Beer's law to combine probe beam absorption through many discrete thin segments, replicating the broadening seen in experimental measurements. The methodology can be easily applied to other non-uniform optical parameters when monitoring total spectral transmission or phase delay. Field non-uniformity is present in standing waves of unmatched waveguides and glass vapor cells, which are generally due to source characteristics and environmental reflections. We present broadening and distortion effects caused by various types of electric-field distributions, and compare this model to results obtained from measured atomic spectra.

Study of Angle of Arrival Estimation with Linear Arrays of Simulated Rydberg Atom Receivers

“…RydIQule also assumes the E-field will be uniform across the optical volume. However, a spatially-varying E-field will likely further degrade the AoA performance [12]. Lastly, the RF signal was chosen to be approximately 7 MHz below the LO frequency for two reasons.…”