Investigating electromagnetically induced transparency spectral lineshape distortion due to non-uniform fields in Rydberg-atom electrometry
Andrew P. Rotunno, Christopher L. Holloway, Nikunjkumar Prajapati, Samuel Berweger, Alexandra B. Artusio‐Glimpse, Roger C. Brown, Matthew T. Simons, Amy K. Robinson, Baran Kayim, Michael A. Viray, Jasmine Jones, Brian C. Sawyer, Robert Wyllie, Thad Walker, Richard W. Ziolkowski, Steven R. Jefferts, Steven Geibel, Jonathan M. Wheeler, Eric Imhof
Abstract
We investigate the effects of spatially non-uniform radio-frequency electric (E) field amplitudes on the spectral line shapes of electromagnetically induced transparency (EIT) signals in Rydberg atomic systems used in electrometry (i.e., the metrology of E-field strengths). Spatially non-uniform fields distort the EIT spectra from that of an ideal case, and understanding this distortion is important in the development of Rydberg atom-based sensors, as these distortions can limit accuracy and sensitivity. To characterize this distortion, we present a model that approximates the atom vapor as multi-layered media and then uses Beer’s law to combine the absorption through its many discrete thin segments. We present a set of expected line distortions caused by various RF electric-field distributions found in practice. This provides an intuitive diagnostic tool for experiments. We compare this model to measured experimental atomic spectra in both two-photon and three-photon excitation schemes in the presence of non-uniform radio-frequency fields. We show that we can accurately model and reproduce the EIT lineshape distortion observed in these experimental data.