Rydberg Atom-Based Radio Frequency Electrometry: Enhancement of the Self-Calibrated Autler-Townes Sensing Mode

We describe experiments relevant to Rydberg atom-based sensing. In Rydberg atom-based sensing, atoms contained in a vapor cell are used as a probe of an incident radio frequency electric field. We present a novel approach based on a collinear three-photon read-out and detection scheme, which extends the sensing range of the self-calibrated Autler-Townes sensing mode to lower electric field strengths. We demonstrate proof of concept and present concrete results from first experiments. We show that we are able to measure electric field strengths below 1 mV/cm in the self-calibrated Autler-Townes regime for a radial dipole moment of 2206 ea0 for a transition at 10.7 GHz. We measure an Autler-Townes splitting of 503(6) kHz, which is equivalent to a radio frequency electric field strength of micro-V/cm.