1
|
Bondza SA, Leopold T, Schwarz R, Lisdat C. Achromatic, planar Fresnel-reflector for a single-beam magneto-optical trap. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:013202. [PMID: 38270499 DOI: 10.1063/5.0174674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 12/19/2023] [Indexed: 01/26/2024]
Abstract
We present a novel achromatic, planar, periodic mirror structure for single-beam magneto-optical trapping and demonstrate its use in the first- and second-stage cooling and trapping for different isotopes of strontium. We refer to it as a Fresnel magneto-optical trap (MOT) as the structure is inspired by Fresnel lenses. By design, it avoids many of the problems that arise for multi-color cooling using planar structures based on diffraction gratings, which have been the dominant planar structures to be used for single-beam trapping thus far. In addition to a complex design process and cost-intensive fabrication, diffraction gratings suffer from their inherent chromaticity, which causes different axial displacements of trap volumes for different wavelengths and necessitates trade-offs in their diffraction properties and achievable trap depths. In contrast, the Fresnel-reflector structure presented here is a versatile, easy-to-manufacture device that combines achromatic beam steering with the advantages of a planar architecture. It enables miniaturizing trapping systems for alkaline-earth-like atoms with multiple cooling transitions as well as multi-species trapping in the ideal tetrahedral configuration and within the same volume above the structure. Our design presents a novel approach for the miniaturization of cold-atom systems based on single-beam MOTs and enables the widespread adoption of these systems.
Collapse
Affiliation(s)
- S A Bondza
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
- Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
| | - T Leopold
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
- Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
| | - R Schwarz
- Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
| | - C Lisdat
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| |
Collapse
|
2
|
Burrow OS, Fasano RJ, Brand W, Wright MW, Li W, Ludlow AD, Riis E, Griffin PF, Arnold AS. Optimal binary gratings for multi-wavelength magneto-optical traps. OPTICS EXPRESS 2023; 31:40871-40880. [PMID: 38041377 DOI: 10.1364/oe.498606] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 11/12/2023] [Indexed: 12/03/2023]
Abstract
Grating magneto-optical traps are an enabling quantum technology for portable metrological devices with ultracold atoms. However, beam diffraction efficiency and angle are affected by wavelength, creating a single-optic design challenge for laser cooling in two stages at two distinct wavelengths - as commonly used for loading, e.g., Sr or Yb atoms into optical lattice or tweezer clocks. Here, we optically characterize a wide variety of binary gratings at different wavelengths to find a simple empirical fit to experimental grating diffraction efficiency data in terms of dimensionless etch depth and period for various duty cycles. The model avoids complex 3D light-grating surface calculations, yet still yields results accurate to a few percent across a broad range of parameters. Gratings optimized for two (or more) wavelengths can now be designed in an informed manner suitable for a wide class of atomic species enabling advanced quantum technologies.
Collapse
|
3
|
Li D, He W, Shi S, Wu B, Xiao Y, Lin Q, Li L. Review of Atom Chips for Absolute Gravity Sensors. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23115089. [PMID: 37299815 DOI: 10.3390/s23115089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/07/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023]
Abstract
As a powerful tool in scientific research and industrial technologies, the cold atom absolute gravity sensor (CAGS) based on cold atom interferometry has been proven to be the most promising new generation high-precision absolute gravity sensor. However, large size, heavy weight, and high-power consumption are still the main restriction factors of CAGS being applied for practical applications on mobile platforms. Combined with cold atom chips, it is possible to drastically reduce the complexity, weight, and size of CAGS. In this review, we started from the basic theory of atom chips to chart a clear development path to related technologies. Several related technologies including micro-magnetic traps, micro magneto-optical traps, material selection, fabrication, and packaging methods have been discussed. This review gives an overview of the current developments in a variety of cold atom chips, and some actual CAGS systems based on atom chips are also discussed. We summarize by listing some of the challenges and possible directions for further development in this area.
Collapse
Affiliation(s)
- Dezhao Li
- Zhejiang Provincial Key Laboratory of Quantum Precision Measurement, Collaborative Innovation Center for Information Technology in Biological and Medical Physics, College of Science, Zhejiang University of Technology, Hangzhou 310023, China
| | - Wenfeng He
- Zhejiang Provincial Key Laboratory of Quantum Precision Measurement, Collaborative Innovation Center for Information Technology in Biological and Medical Physics, College of Science, Zhejiang University of Technology, Hangzhou 310023, China
| | - Shengnan Shi
- Zhejiang Provincial Key Laboratory of Quantum Precision Measurement, Collaborative Innovation Center for Information Technology in Biological and Medical Physics, College of Science, Zhejiang University of Technology, Hangzhou 310023, China
| | - Bin Wu
- Zhejiang Provincial Key Laboratory of Quantum Precision Measurement, Collaborative Innovation Center for Information Technology in Biological and Medical Physics, College of Science, Zhejiang University of Technology, Hangzhou 310023, China
| | - Yuhua Xiao
- Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou 730000, China
| | - Qiang Lin
- Zhejiang Provincial Key Laboratory of Quantum Precision Measurement, Collaborative Innovation Center for Information Technology in Biological and Medical Physics, College of Science, Zhejiang University of Technology, Hangzhou 310023, China
| | - Long Li
- Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433, China
| |
Collapse
|
4
|
Kłos J, Tiesinga E. Elastic and glancing-angle rate coefficients for heating of ultracold Li and Rb atoms by collisions with room-temperature noble gases, H 2, and N 2. J Chem Phys 2023; 158:014308. [PMID: 36610981 DOI: 10.1063/5.0124062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Trapped ultracold alkali-metal atoms can be used to measure pressure in the ultra-high-vacuum and XHV pressure regimes, those with p < 10-6 Pa. This application for ultracold atoms relies on precise knowledge of collision rate coefficients of alkali-metal atoms with residual room-temperature atoms and molecules in the ambient vacuum or with deliberately introduced gasses. Here, we determine combined elastic and inelastic rate coefficients as well as glancing-angle rate coefficients for ultracold 7Li and 87Rb with room-temperature noble gas atoms as well as H2 and 14N2 molecules. Glancing collisions are those processes where only little momentum is transferred to the alkali-metal atom and this atom is not ejected from its trap. Rate coefficients are found by performing quantum close-coupling scattering calculations using ab initio ground-state electronic Born-Oppenheimer potential energy surfaces. The potentials for Li and Rb with noble gas atoms and also for Rb(2S)-H2(XΣg +) and Rb(2S)-N2(X1Σg +) systems are based on the non-relativistic spin-restricted coupled-cluster method with single, double, and noniterative triple excitations [RCCSD(T)]. For Li(2S)-N2(X1Σg +), the potential is computed at the explicitly correlated spin-restricted RCCSD(T)-F12 level. For Rb, Kr, and Xe atoms, scalar relativistic corrections to the core electrons have been included, while second-order spin-orbit corrections from the valence electrons have been estimated. Data for Li-H2 and Li-He were taken from the existing literature. We estimate standard uncertainties of the rate coefficients by comparing rate coefficients calculated using potentials found with electronic basis sets of increasing size, including estimates of relativistic spin-orbit corrections and the uncertainty of the van der Waals coefficients. The relative uncertainties of rate coefficients are 1%-2% with the exception of 7Li or 87Rb colliding with 20Ne. Those have relative uncertainties of 9% and 8%, respectively. We also show that a commonly used semiclassical approximation for the total elastic rate coefficient agrees with the quantum calculations to 10% with the exception of 7Li and 87Rb collisions with H2, where the semiclassical value underestimates the quantum value by 20%.
Collapse
Affiliation(s)
- Jacek Kłos
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - Eite Tiesinga
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| |
Collapse
|
5
|
Barker DS, Acharya BP, Fedchak JA, Klimov NN, Norrgard EB, Scherschligt J, Tiesinga E, Eckel SP. Precise quantum measurement of vacuum with cold atoms. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:121101. [PMID: 36586922 DOI: 10.1063/5.0120500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/09/2022] [Indexed: 06/17/2023]
Abstract
We describe the cold-atom vacuum standards (CAVS) under development at the National Institute of Standards and Technology (NIST). The CAVS measures pressure in the ultra-high and extreme-high vacuum regimes by measuring the loss rate of sub-millikelvin sensor atoms from a magnetic trap. Ab initio quantum scattering calculations of cross sections and rate coefficients relate the density of background gas molecules or atoms to the loss rate of ultra-cold sensor atoms. The resulting measurement of pressure through the ideal gas law is traceable to the second and the kelvin, making it a primary realization of the pascal. At NIST, two versions of the CAVS have been constructed: a laboratory standard used to achieve the lowest possible uncertainties and pressures, and a portable version that is a potential replacement for the Bayard-Alpert ionization gauge. Both types of CAVSs are connected to a combined extreme-high vacuum flowmeter and dynamic expansion system to enable sensing of a known pressure of gas. In the near future, we anticipate being able to compare the laboratory scale CAVS, the portable CAVS, and the flowmeter/dynamic expansion system to validate the operation of the CAVS as both a standard and vacuum gauge.
Collapse
Affiliation(s)
- Daniel S Barker
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Bishnu P Acharya
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - James A Fedchak
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Nikolai N Klimov
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Eric B Norrgard
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Julia Scherschligt
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Eite Tiesinga
- Quantum Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Stephen P Eckel
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| |
Collapse
|
6
|
A compact cold-atom interferometer with a high data-rate grating magneto-optical trap and a photonic-integrated-circuit-compatible laser system. Nat Commun 2022; 13:5131. [PMID: 36050325 PMCID: PMC9436985 DOI: 10.1038/s41467-022-31410-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 06/15/2022] [Indexed: 12/05/2022] Open
Abstract
The extreme miniaturization of a cold-atom interferometer accelerometer requires the development of novel technologies and architectures for the interferometer subsystems. Here, we describe several component technologies and a laser system architecture to enable a path to such miniaturization. We developed a custom, compact titanium vacuum package containing a microfabricated grating chip for a tetrahedral grating magneto-optical trap (GMOT) using a single cooling beam. In addition, we designed a multi-channel photonic-integrated-circuit-compatible laser system implemented with a single seed laser and single sideband modulators in a time-multiplexed manner, reducing the number of optical channels connected to the sensor head. In a compact sensor head containing the vacuum package, sub-Doppler cooling in the GMOT produces 15 μK temperatures, and the GMOT can operate at a 20 Hz data rate. We validated the atomic coherence with Ramsey interferometry using microwave spectroscopy, then demonstrated a light-pulse atom interferometer in a gravimeter configuration for a 10 Hz measurement data rate and T = 0–4.5 ms interrogation time, resulting in Δg/g = 2.0 × 10−6. This work represents a significant step towards deployable cold-atom inertial sensors under large amplitude motional dynamics. Cold-atom interferometers have been miniaturized towards fieldable quantum inertial sensing applications. Here the authors demonstrate a compact cold-atom interferometer using microfabricated gratings and discuss the possible use of photonic integrated circuits for laser systems.
Collapse
|
7
|
McGilligan JP, Gallacher K, Griffin PF, Paul DJ, Arnold AS, Riis E. Micro-fabricated components for cold atom sensors. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:091101. [PMID: 36182455 DOI: 10.1063/5.0101628] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/02/2022] [Indexed: 06/16/2023]
Abstract
Laser cooled atoms have proven transformative for precision metrology, playing a pivotal role in state-of-the-art clocks and interferometers and having the potential to provide a step-change in our modern technological capabilities. To successfully explore their full potential, laser cooling platforms must be translated from the laboratory environment and into portable, compact quantum sensors for deployment in practical applications. This transition requires the amalgamation of a wide range of components and expertise if an unambiguously chip-scale cold atom sensor is to be realized. We present recent developments in cold-atom sensor miniaturization, focusing on key components that enable laser cooling on the chip-scale. The design, fabrication, and impact of the components on sensor scalability and performance will be discussed with an outlook to the next generation of chip-scale cold atom devices.
Collapse
Affiliation(s)
- J P McGilligan
- SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - K Gallacher
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - P F Griffin
- SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - D J Paul
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - A S Arnold
- SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - E Riis
- SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| |
Collapse
|
8
|
Barker DS, Norrgard EB, Klimov NN, Fedchak JA, Scherschligt J, Eckel S. Λ-enhanced gray molasses in a tetrahedral laser beam geometry. OPTICS EXPRESS 2022; 30:9959-9970. [PMID: 35299409 PMCID: PMC9843705 DOI: 10.1364/oe.444711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
We report the observation of sub-Doppler cooling of lithium using an irregular-tetrahedral laser beam arrangement, which is produced by a nanofabricated diffraction grating. We are able to capture 11(2)% of the lithium atoms from a grating magneto-optical trap into Λ-enhanced D1 gray molasses. The molasses cools the captured atoms to a radial temperature of 60(9) μK and an axial temperature of 23(3) μK. In contrast to results from conventional counterpropagating beam configurations, we do not observe cooling when our optical fields are detuned from Raman resonance. An optical Bloch equation simulation of the cooling dynamics agrees with our data. Our results show that grating magneto-optical traps can serve as a robust source of cold atoms for tweezer-array and atom-chip experiments, even when the atomic species is not amenable to sub-Doppler cooling in bright optical molasses.
Collapse
Affiliation(s)
- D. S. Barker
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - E. B. Norrgard
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - N. N. Klimov
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - J. A. Fedchak
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - J. Scherschligt
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - S. Eckel
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| |
Collapse
|
9
|
Sun X, Rickard WDA, Sparkes BM, White BR, Offer RF, Luiten AN, Ironside CN. Rapid prototyping of grating magneto-optical traps using a focused ion beam. OPTICS EXPRESS 2021; 29:37733-37746. [PMID: 34808840 DOI: 10.1364/oe.439479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
We have developed a rapid prototyping approach for creating custom grating magneto-optical traps using a dual-beam system combining a focused ion beam and a scanning electron microscope. With this approach we have created both one- and two-dimensional gratings of up to 400 µm × 400 µm in size with structure features down to 100 nm, periods of 620 nm, adjustable aspect ratios (ridge width : depth ∼ 1 : 0.3 to 1 : 1.4) and sidewall angles up to 71°. The depth and period of these gratings make them suitable for holographic trapping and cooling of neutral ytterbium on the 1S0 → 1P1 399 nm transition. Optical testing of the gratings at this wavelength has demonstrated a total first order diffraction of 90% of the reflected light. This work therefore represents a fast, high resolution, programmable and maskless alternative to current photo and electron beam lithography-based procedures and provides a time efficient process for prototyping of small period, high aspect ratio grating magneto-optical traps and other high resolution structures.
Collapse
|
10
|
Golovizin A, Tregubov D, Mishin D, Provorchenko D, Kolachevsky N. Compact magneto-optical trap of thulium atoms for a transportable optical clock. OPTICS EXPRESS 2021; 29:36734-36744. [PMID: 34809077 DOI: 10.1364/oe.435105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
We have developed a compact vacuum system for laser cooling and spectroscopy of neutral thulium atoms. Compactness is achieved by obviating a classical Zeeman slower section and placing an atomic oven close to a magneto-optical trap (MOT), specifically at the distance of 11 cm. In this configuration, we significantly gained in solid angle of an atomic beam, which is affected by MOT laser beams, and reached 1 million atoms loaded directly in the MOT with only 15 mW of MOT cooling beams net power. By exploiting Zeeman-like deceleration of atoms with an additional laser beam and tailoring the MOT magnetic field gradient with a small magnetic coil, we demonstrated trapping of up to 13 million atoms. These results show great perspective of the developed setup for realizing a compact high-performance optical atomic clock based on thulium atoms.
Collapse
|
11
|
Seo S, Lee JH, Lee SB, Park SE, Seo MH, Park J, Kwon TY, Hong HG. Maximized atom number for a grating magneto-optical trap via machine-learning assisted parameter optimization. OPTICS EXPRESS 2021; 29:35623-35639. [PMID: 34808993 DOI: 10.1364/oe.437991] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
We present a parameter set for obtaining the maximum number of atoms in a grating magneto-optical trap (gMOT) by employing a machine learning algorithm. In the multi-dimensional parameter space, which imposes a challenge for global optimization, the atom number is efficiently modeled via Bayesian optimization with the evaluation of the trap performance given by a Monte-Carlo simulation. Modeling gMOTs for six representative atomic species - 7Li, 23Na, 87Rb, 88Sr, 133Cs, 174Yb - allows us to discover that the optimal grating reflectivity is consistently higher than a simple estimation based on balanced optical molasses. Our algorithm also yields the optimal diffraction angle which is independent of the beam waist. The validity of the optimal parameter set for the case of 87Rb is experimentally verified using a set of grating chips with different reflectivities and diffraction angles.
Collapse
|
12
|
Enhanced observation time of magneto-optical traps using micro-machined non-evaporable getter pumps. Sci Rep 2020; 10:16590. [PMID: 33024172 PMCID: PMC7538997 DOI: 10.1038/s41598-020-73605-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 09/15/2020] [Indexed: 11/08/2022] Open
Abstract
We show that micro-machined non-evaporable getter pumps (NEGs) can extend the time over which laser cooled atoms can be produced in a magneto-optical trap (MOT), in the absence of other vacuum pumping mechanisms. In a first study, we incorporate a silicon-glass microfabricated ultra-high vacuum (UHV) cell with silicon etched NEG cavities and alumino-silicate glass (ASG) windows and demonstrate the observation of a repeatedly-loading MOT over a 10 min period with a single laser-activated NEG. In a second study, the capacity of passive pumping with laser activated NEG materials is further investigated in a borosilicate glass-blown cuvette cell containing five NEG tablets. In this cell, the MOT remained visible for over 4 days without any external active pumping system. This MOT observation time exceeds the one obtained in the no-NEG scenario by almost five orders of magnitude. The cell scalability and potential vacuum longevity made possible with NEG materials may enable in the future the development of miniaturized cold-atom instruments.
Collapse
|
13
|
Sitaram A, Elgee PK, Campbell GK, Klimov NN, Eckel S, Barker DS. Confinement of an alkaline-earth element in a grating magneto-optical trap. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:103202. [PMID: 33138581 DOI: 10.1063/5.0019551] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/30/2020] [Indexed: 05/22/2023]
Abstract
We demonstrate a compact magneto-optical trap (MOT) of alkaline-earth atoms using a nanofabricated diffraction grating chip. A single input laser beam, resonant with the broad 1S0 → 1P1 transition of strontium, forms the MOT in combination with three diffracted beams from the grating chip and a magnetic field produced by permanent magnets. A differential pumping tube limits the effect of the heated, effusive source on the background pressure in the trapping region. The system has a total volume of around 2.4 l. With our setup, we have trapped up to 5 × 106 88Sr atoms at a temperature of ∼6 mK, and with a trap lifetime of ∼1 s. Our results will aid the effort to miniaturize quantum technologies based on alkaline-earth atoms.
Collapse
Affiliation(s)
- A Sitaram
- Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - P K Elgee
- Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - G K Campbell
- Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - N N Klimov
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - S Eckel
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - D S Barker
- Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| |
Collapse
|
14
|
Henderson VA, Johnson MYH, Kale YB, Griffin PF, Riis E, Arnold AS. Optical characterisation of micro-fabricated Fresnel zone plates for atomic waveguides. OPTICS EXPRESS 2020; 28:9072-9081. [PMID: 32225520 DOI: 10.1364/oe.388897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
We optically assess Fresnel zone plates (FZPs) that are designed to guide cold atoms. Imaging of various ring patterns produced by the FZPs gives an average RMS error in the brightest part of the ring of 3% with respect to trap depth. This residue is attributed to the imaging system, incident beam shape and FZP manufacturing tolerances. Axial propagation of the potentials is presented experimentally and through numerical simulations, illustrating prospects for atom guiding without requiring light sheets.
Collapse
|
15
|
Eckel S, Barker DS, Norrgard EB, Scherschligt J. PyLCP: A Python package for computing laser cooling physics. COMPUTER PHYSICS COMMUNICATIONS 2020; 270:10.1016/j.cpc.2021.108166. [PMID: 36733946 PMCID: PMC9890571 DOI: 10.1016/j.cpc.2021.108166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We present a Python object-oriented computer program for simulating various aspects of laser cooling physics. Our software is designed to be both easy to use and adaptable, allowing the user to specify the level structure, magnetic field profile, or the laser beams' geometry, detuning, and intensity. The program contains three levels of approximation for the motion of the atom, applicable in different regimes offering cross checks for calculations and computational efficiency depending on the physical situation. We test the software by reproducing well-known phenomena, such as damped Rabi flopping, electromagnetically induced transparency, stimulated Raman adiabatic passage, and optical molasses. We also use our software package to quantitatively simulate recoil-limited magneto-optical traps, like those formed on the narrow 1S0 → 3P1 transition in 88Sr and 87Sr.
Collapse
Affiliation(s)
- Stephen Eckel
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Corresponding author.
| | - Daniel S. Barker
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Eric B. Norrgard
- Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899, USA
| | - Julia Scherschligt
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| |
Collapse
|