Modern RF Measurements With Hot Atoms: A Technology Review of Rydberg Atom-Based Radio Frequency Field Sensors

Modeling Line Broadening and Distortion Due to Spatially Non-Uniform Fields in Rydberg Electrometry

“…The Rydberg resonant field measurement scheme has been used previously to give traceable measurements of electric field amplitudes. The corresponding simulation of transmission for a four-level system is welldocumented [1][2][3][4] . Precision measurements using spectroscopy are often limited by the linewidths observed, which can become broadened by non-uniform energy shifts over the observation volume.…”

“…In recent years, Rydberg atom spectroscopy has been a fruitful method for making traceable measurements of radio-frequency (RF) electric (E) field amplitudes. Other electric and magnetic fields effects can also be observed via transmission spectroscopy [1][2][3][4] . In these sensors, Rydberg atom energies are observed via electromagnetically induced transparency (EIT).…”

“…Spectral lines can be split linearly with applied resonant electric fields via the Autler-Townes (AT) effect, and off-resonance, lines are shifted in energy by ac Stark effects. By measuring these effects carefully, we can measure amplitude [1][2][3][4][5][6][7][8][9] , polarization 10,11 , and phase 12,13 of an RF field in a way that is traceable to International System of Units (SI) 3 with various applications 4 .…”

Phase Retrieval for Rydberg Quantum Arrays

“…Recent work at the National Institute of Standards and Technology (NIST) and many other institutions has demonstrated the feasibility of using Rydberg atom probes to provide traceable measurements of electric field intensity [18]. These quantum probes have many unique features that set them apart from traditional antennas including exactly defined response functions based on quantum mechanics allowing for direct field strength traceability to the International System of Units (SI) [19][20][21][22][23], a highly transparent probe head to RF fields made only of dielectric materials [24,25], direct down-conversion of the RF field by the atoms reducing the need for back-end electronics [26], and intrinsic ultra-wideband tunability from kilohertz frequencies to terahertz frequencies using a single probe and a tunable laser [21,27].…”

The effect of electric field inhomogeneity in Rydberg atom-based electric field sensing

“…In a typical measurement a Rydberg state of an alkali metal vapor is prepared using two spatially overlapped counterpropagating lasers. 4 These two lasers -probe and coupling lasers (ω P and ω C , respectively) -probe the Rydberg state via the electromagnetically induced transparency (EIT) of the probe laser, with the cesium states used in this work illustrated in Fig. 1(A).…”