A superheterodyne Rydberg S-band receiver

Our superheterodyne Rydberg S-band receiver, whose local oscillator is generated inside the vapour cell by an atomic transition loop, is published in Applied Optics 64, 5813.

Multi-tone mixing removes the need for a local oscillator at the signal frequency, keeping the sensor stealthy and all-optical; it works in the S-band used by Wi-Fi without interfering with the signal.