Atom-based receiver for amplitude-modulated baseband signals in high-frequency radio communication

An atom-based sensor is used to retrieve baseband signals modulated onto a microwave carrier. The 60S1/2 level of cesium atoms in a vapor cell is optically probed via electromagnetically induced transparency. A 16.98-GHz carrier is resonant with the 60S1/2 → 60P1/2 transition, resulting in an Autler–Townes (AT) splitting. Amplitude modulation (AM) results in a variation of the AT splitting, which is processed to retrieve the AM baseband signals. The optically retrieved signal has a fidelity of >95%. We demonstrate a baseband bandwidth of the receiver of about 60 kHz and a dynamic range of about 30 dB.