Continuous radio-frequency electric-field detection through adjacent Rydberg resonance tuning

Abstract

We demonstrate the use of multiple atomic-level Rydberg-atom schemes for continuous frequency detection of radio frequency (RF) fields. Resonant detection of RF fields by electromagneticallyinduced transparency and Autler-Townes (AT) in Rydberg atoms is typically limited to frequencies within the narrow bandwidth of a Rydberg transition. By applying a second field resonant with an adjacent Rydberg transition, far-detuned fields can be detected through a two-photon resonance AT splitting. This two-photon AT splitting method is several orders of magnitude more sensitive than off-resonant detection using the Stark shift. We present the results of various experimental configurations and a theoretical analysis to illustrate the effectiveness of this multiple level scheme. These results show that this approach allows for the detection of frequencies in continuous band between resonances with adjacent Rydberg states.

Sensitivity improvement of Rydberg atom-based microwave sensing via electromagnetically induced transparency

“…The enhancement of dynamic optical response by RF detuning can be understood by a theoretical simulation based on the optical Bloch equation considering the four energy levels [10,11,13,22,34,36]. Taking the energy level of the intermediate state 5P 3/2 as a reference, the Hamiltonian H can be expressed as a matrix form…”

“…Rydberg atoms in highly excited states with one or more electrons of large principal quantum numbers are sensitive to electric fields, very suitable to manufacture atom-based sensor for detecting and receiving communication signals [1]. It has been widely investigated thoroughly both theoretically and experimentally throughout the last decades [2][3][4][5][6][7][8][9][10][11][12][13]. This type of sensors can replace the front-end components and electronics in a conventional antenna/receiver system [14,15], since they have potential advantages over conventional systems.…”

VHF/UHF detection using high angular momentum Rydberg states

“…This can be done by using portable laser systems and operating in an anechoic chamber, since λ rf is comparable to or larger than many optical elements. Furthermore, this approach is compatible with using auxiliary rf fields to Stark-tune the desired rf frequency [43,51] offering continuous tuning between atomic transitions.…”

“…We develop a numerical model to benchmark our experimental data and compute fundamental sensitivity limits. We use a master equation formalism to simulate the light-atom interaction, as in previous work [33,43]. We numerically compute the steady-state density matrix for the thermal 87 Rb sample.…”

Bright and dark Autler-Townes states in the atomic Rydberg multilevel spectroscopy

“…When one transition is driven by a intense laser, the second transition spectrum is composed by a resonant doublet with the separation between the two components determined by the laser electric field. This process, well characterised in atomic/molecular and solid state spectroscopy, has received recently a new interest within a different context: the precise determination of a microwave (mw) field amplitude for calibration purposes as in [9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]. The mw radiation is applied to cold atoms in Rydberg states where the electric dipole moment is very large, such that even a weak mw field produces AT splitting.…”