Detuning radio-frequency electrometry using Rydberg atoms in a room-temperature vapor cell

Traceable radio-frequency electric field measurements with high sensitivity have been demonstrated from the centimeter wave to the millimeter wave using room-temperature Rydberg atoms. Here, we investigate the splitting spectra of electromagnetically induced transparency induced by a radio-frequency electric field, which is detuned from the resonant frequency of transitions between two Rydberg states, 47D5/2 ↔ 48P3/2. By varying the detuning of the radio-frequency electric field, we measure the separation between the two peaks, and in particular their relative height. The resulting measured resonant transition frequency between two Rydberg states is found to exhibit a visible change when the power of the radio-frequency electric field is varied, thus causing uncertainty in the traceable radio-frequency electric field measurement. Further, the effect of detuning of the probe light on the radio-frequency electric field measurement is presented.