Satellite radio detection via dual-microwave Rydberg spectroscopy

Rydberg electric field sensors exploit the structured multitude of electronic transitions between Rydberg atomic states. In this way, they can detect electric fields with frequencies spanning DC to THz. However, difficulty accessing resonant transitions at ultra-high frequencies (UHF, 0.3-30 GHz) and below hinders their applicability within this ubiquitous band of the world’s wireless communications infrastructure. We present a Rydberg electric field sensor operating in the UHF band using a resonant dual-optical dual-microwave spectroscopy scheme. This enables access to transitions with lower resonant frequencies, and higher angular momentum (L = 3→4), than those typically used in Rydberg sensors. We measure the resonant sensitivity of our system at 2.3 GHz to be 70(5) µVm
⁻¹
Hz
^−1/2
, 50 times better than the measured sensitivity with a far off-resonant probing scheme at this frequency. Moreover, we demonstrate the effectiveness of this scheme by measuring Sirius XM satellite radio (2.320 - 2.345 GHz) received outside the laboratory and rebroadcast onto the atoms.