arXiv subjects

Donald W. Booth

Publications and source records attributed to Donald W. Booth.

5 recordsLinked to original sources

arXiv2023

Implementing an electronic sideband offset lock for precision spectroscopy in radium

We demonstrate laser frequency stabilization with at least 6 GHz of offset tunability using an in-phase/quadrature (IQ) modulator to generate electronic sidebands (ESB) on a titanium sapphire laser at 714 nm and we apply this technique to the precision spectroscopy of $^{226}$Ra, and $^{225}$Ra. By locking the laser to a single resonance of a high finesse optical cavity and adjusting the lock offset, we determine the frequency difference between the magneto-optical trap (MOT) transitions in the two isotopes to be $2630.0\pm0.3$ MHz, a factor of 29 more precise than the previously available data. Using the known value of the hyperfine splitting of the $^{3}P_{1}$ level, we calculate the isotope shift for the $^{1}S_{0}$ to $^{3}P_{1}$ transition to be $2267.0\pm2.2$ MHz, which is a factor of 8 more precise than the best available value. Our technique could be applied to countless other atomic systems to provide unprecedented precision in isotope shift spectroscopy and other relative frequency comparisons.

physics.atom-ph↗

arXiv2023

Rydberg Atom Sensors in Multichromatic Radio Frequency Fields

Rydberg atom-based sensors are a new type of radio frequency sensor that is inherently quantum mechanical. Several configurations of the sensor use a local oscillator to determine the properties of the target radio frequency field. We explain how the physics of Rydberg atom-based sensors in two or more radio frequency fields can be precisely described by a multiply dressed Jaynes-Cummings model. Studying Rydberg atom-based sensors in two or more near resonant radio frequency fields is important for understanding how interfering signals as well as the local oscillator can affect measurements. Studies, so far, focus on a simplified approximation for the local oscillator-target field interaction that uses an analogy to radio frequency heterodyning. The atom acts as a medium for exchanging electromagnetic field excitations of the field modes whose spectrum is a ladder. The Jaynes-Cummings states and their avoided crossings can be used to determine the properties of the radio frequency fields. Radio frequency field sensitivity enhancement for non-resonant radio frequencies is achieved and self-calibrated measurements are recovered under specific conditions described by the theory.

physics.atom-ph↗

arXiv2022

Rydberg atom-based Electrometry Using a Self-Heterodyne Frequency Comb Readout and Preparation Scheme

Atom-based radio frequency electromagnetic field sensing using atomic Rydberg states is a promising technique that has recently attracted significant interest. Its unique advantages, such as extraordinary bandwidth, self-calibration and all-dielectric sensors, are a tangible improvement over antenna-based methods in applications such as test and measurement, and development of broad bandwidth receivers. Here, we demonstrate how an optical frequency comb can be used to acquire data in the Autler-Townes regime of Rydberg atom-based electrometry in a massively parallel fashion, eliminating the need for laser scanning. Two-photon electromagnetically induced transparency read-out and preparation of cesium is used for the demonstration. A flat, quasi-continuous optical comb is generated with the probe laser at 852 nm using an electro-optic modulator and arbitrary waveform generator. A single frequency coupling laser at 509 nm is tuned to the Rydberg launch state. An enhanced transmission signal is obtained using self-heterodyne spectroscopy. The comb signal is beat against a local oscillator derived from the single frequency probe laser on a fast photodiode. The transmission of each probe laser comb tooth is observed. We resolve electromagnetically induced transparency peaks with linewidths below 5 MHz, with and without laser locking. Radio frequency electromagnetic fields as low as 66 $μ$Vcm$^{-1}$ are detected with sensitivities of 2.3 $μ$Vcm$^{-1}$Hz$^{-1/2}$. The method offers a significant advantage for reading-out electromagnetically induced transparency and Autler-Townes splitting as neither laser needs to be scanned and slow frequency drifts can be tolerated in some applications. The method enables the detection of the amplitude of a pulsed radio frequency electromagnetic field when the incoming pulse Autler-Townes splits the electromagnetically induced transparency peak.

physics.atom-ph↗

arXiv2017

Reducing the sensitivity of Rydberg atoms to dc electric fields using two-frequency ac field dressing

We propose a method for reducing the sensitivity of atomic ground to Rydberg transitions to stray dc electric fields, using microwave-induced dressing of Rydberg states. Calculations are presented for the Cs $\state{90S}{1/2}$ and $\state{90P}{3/2}$ states. With zero dc bias electric field, a two-frequency ac field is used to simultaneously reduce the sensitivity of both states to dc field variations. The sensitivity reduction is a factor of 95 for the $\state{90S}{1/2}$ state and a factor of 1600 for the $\state{90P}{3/2}, m_J=3/2$ state. We also show how the two-frequency ac field can be used to cancel both second- and fourth-order terms in the polarizability of a single Rydberg state. These results are relevant to improving the stability of experiments that seek to excite Rydberg atoms in the proximity of charged surfaces.

physics.atom-ph↗

arXiv2009

Observation of Cs Rydberg atom macrodimers

We report the observation of cold Cs Rydberg atom molecules bound at internuclear separations of R~3-9 um. The bound states result from avoided crossings between Rydberg atom pair interaction potentials in an applied electric field. The molecular states can be modified by changing the applied electric field. The molecules are observed by mapping the radial separation of the two Rydberg atoms as a function of time delay between excitation and detection using the Coulomb repulsion of the ions after pulsed field ionization. Measurements were performed for 63D+65D, 64D+66D, 65D+67D, and 66D+68D pairs. The experiment is in good agreement with calculations of the pair interactions for these states.

physics.atom-ph↗