A Cs Rydberg Atomic Microwave Oscillator for Electric Field Sensing

In this paper, we report an atomic oscillator in Ku band and its application for electric field (E-field) sensing with Cs Rydberg atoms in a room-temperature vapor cell. The oscillator is associated with the Cs Rydberg transition of 36
²
D
5/2
– 37
²
P
3/2
at 16.316 GHz which is generated with a two-laser double-resonance excitation. We characterized the energetics and the dipole moment of the Rydberg transition and used Electromagnetically Induced Transparency (EIT) and Autler-Townes (AT) effects for detecting continuous and amplitude/frequency modulated microwave E-fields. To enhance the oscillator’s response to weak signals, a superheterodyne technique was incorporated into the Rydberg oscillator system, which resulted in an improvement in the oscillator’s sensitivity by 100 times. Furthermore, our modeling shows that the Cs Rydberg atomic oscillator can be tuned to broad frequency ranges from MHz to THz for various RF applications.