arXiv:2110.10673

Engineering atomic polarization with microwave-assisted optical pumping

Tretiakov, A., C. A. Potts, Yapeng Lu, J. P. Davis, Lindsay J. LeBlanc

Published Oct 20, 2021• 0 citations

Abstract

Polarized atomic ensembles play a crucial role in precision measurements. We demonstrate a novel method of creating atomic polarization in an alkali vapor in a continuous-wave regime. The method relies on a combination of optical pumping by a laser beam and microwave transitions due to a cavity-enhanced magnetic field. With this approach, atomic internal angular momentum can be oriented along a static magnetic field at an arbitrary angle with respect to the laser beam. Furthermore, the atomic polarization depends on the microwave parameters, which can be used for microwave-to-optical transduction and microwave-controlled nonlinear magneto-optical rotation.

DOI: 10.48550/arxiv.2110.10673

Related papers

Manipulating optical absorption and polarization using microwave control in an atomic vapor

A Tretiakov, C. A. Potts, B Lu +2 more

Abstract The multiplicity of atomic states (and the transitions between them) offer an innate, coherent platform through which microwave and optical fields effectively interact. In an atomic vapor near room temperature, we combine optical and microwave fields to generate a macroscopic internal angular momentum among the atoms—an atomic polarization—at an arbitrary angle with respect to the optical (laser) beam. This geometric freedom enables microwave control over photonic degrees of freedom, which we use in two demonstrations: using microwave-assisted optical pumping, we can rotate linear polarization through several degrees, and we can control the absorption for specific transitions and polarizations, which has applications for microwave-to-optical transduction.

Journal of Physics PhotonicsFeb 19, 20242 citations

Manipulating optical properties of rubidium through microwave interactions

Tretiakov, Andrei

Information transfer between a microwave field and light, also known as microwave-to optical transduction, is a key area of research in quantum communication technology aimed at developing an interface between the superconducting processing devices operating at microwave frequencies and optical photons used for transferring quantum information over distance. Atomic vapors offer a good platform for such interfaces since they naturally support transitions at microwave and optical frequencies. In this work, we explored microwave-to-optical transduction in rubidium ensembles. We proposed a transduction method based on microwave-optical double resonance, where we can control the ensemble optical properties via non-linear interactions with a microwave magnetic field. With this method, we demonstrate the transduction of an audio signal from frequency-modulated and amplitude-modulated microwave fields to optical intensity modulation. We also present a protocol for engineering atomic spin polarization with microwave-assisted optical pumping and consider its applications for polarization-selective frequency conversion and microwave-controlled optical rotation.

Jan 1, 20210 citations

Magnetometry with Microwave-Assisted Optical Pumping in Warm Rb Vapor and Microfabricated Rb Vapor Cells

Lu, Ying-Ying

Quantum optical sensing is a maturing field that offers the capability to achieve extraor- dinary sensitivity. Atomic magnetometers, for example, now have the capability to detect brain signals and to precisely measure Earth’s gravity field. In optical atomic magnetome- ters, the electronic spins of the atoms in vapor form are aligned in the same direction by “pumping” the ensemble using laser light at a select frequency. Any magnetic field alters the spin states, which changes the optical properties of the vapor, such as the transmission of the laser light, providing a way to measure magnetic fields. After reviewing the theory of atomic structure and atom-light interactions relevant to the research presented here, I describe in the first part of this thesis a vector magnetometry method using microwave-assisted optical pumping, in which a microwave field resonant to the ground state hyperfine splitting of 87Rb pumps an ensemble of warm rubidium vapor, in addition to a strong optical pump beam, and a weaker optical probe beam. I present theoretical details as well as preliminary data demonstrating magnetic field measurements of a DC magnetic field. The measurements were taken when the DC field was aligned at various angles relative to the microwave magnetic field alignment. I compare theoretical and experimental differences in the measurements. With new methods for quantum devices comes the need for portability. In the second part of this thesis, we demonstrate the fabrication of millimeter-sized rubidium vapor cells using silicon micro-machining techniques. This method is relatively inexpensive compared to glass-blowing methods and allows rapid, large-scale production. I describe our process flow and demonstrate the presence of rubidium atoms inside our vapor cells. To conclude, suggestions for improvement are discussed.

Jan 1, 20210 citations

Generation of atomic spin orientation with a linearly polarized beam in room-temperature alkali-metal vapor

Patrick Bevington, R. Gartman, Witold Chałupczak

Traditionally, atomic spin orientation is achieved by the transfer of angular momentum from polarized light to an atomic system. We demonstrate the mechanism of orientation generation in room-temperature caesium vapors that combines three elements: optical pumping, nonlinear spin dynamics, and spin-exchange collisions. Through the variation of the spin-exchange relaxation rate, the transition between an aligned and an oriented atomic sample is presented. The observation is performed by monitoring the atomic radio-frequency spectra. The measurement configuration discussed paves the way to simple and robust radio-frequency atomic magnetometers that are based on a single low-power laser diode that approach the performance of multilaser pump-probe systems.

arXiv:1910.06131Physical Review AJan 30, 20209 citations

Practical method for transversely measuring the spin polarization of optically pumped alkali atoms

Zhichao Ding, Jie Yuan, Xingwu Long

Abstract A practical method to measure the spin polarization of optically pumped alkali atoms is demonstrated. In order to realize transverse measurement, the transverse spin component of spin-polarized alkali atoms is created by a rotating exciting magnetic field, and detected using the optical rotation of a near-resonant probe beam for realizing a high detection sensitivity. The dependency of the optical rotation on the spin polarization of 133 Cs atoms is derived theoretically and verified experimentally. By changing the direction of the rotating magnetic field, we realize the transverse measurement of the spin polarization of 133 Cs atoms in either ground-state hyperfine level.

Journal of Physics B Atomic Molecular and Optical PhysicsMay 1, 20185 citations

Amplitude-modulated indirect pumping of spin orientation in low-density cesium vapor

R. Gartman, Witold Chałupczak

A recently demonstrated technique of continuous indirect pumping enables a high level of atomic spin polarization to be generated in thermal alkali-metal vapors, without compromising the coherence lifetime through power broadening from the pump laser. The indirect pumping process combines optical excitation and spin-exchange collisions. Here we describe the pumping process and the role of spin-exchange collisions for the case of amplitude-modulated optical excitation. We demonstrate that effective spin-exchange decoherence is modified by the measurement geometry and dynamics. Decoherence changes are studied through magneto-optical-rotation signals. The studies presented here are particularly important for optimizing the performance of an atomic magnetometer operating in the quantum nondemolition configuration in a nonzero-magnetic-field environment.

Physical Review AMay 26, 201513 citations