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Pick J, Schwarz R, Kruse J, Lisdat C, Klempt C. Compact structures for single-beam magneto-optical trapping of ytterbium. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:073201. [PMID: 38958512 DOI: 10.1063/5.0203308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/26/2024] [Indexed: 07/04/2024]
Abstract
At present, the best optical lattice clocks are based on the spectroscopy of trapped alkaline-earth-like atoms such as ytterbium and strontium. The development of mobile or even space-borne clocks necessitates concepts for the compact laser-cooling and trapping of these atoms with reduced laser requirements. Here, we present two compact and robust achromatic mirror structures for single-beam magneto-optical trapping of alkaline-earth-like atoms using two widely separated optical cooling frequencies. We have compared the trapping and cooling performance of a monolithic aluminum structure that generates a conventional trap geometry to a quasi-planar platform based on a periodic mirror structure for different isotopes of Yb. Compared to prior work with strontium in non-conventional traps, where only bosons were trapped on a narrow line transition, we demonstrate two-stage cooling and trapping of a fermionic alkaline-earth-like isotope in a single-beam quasi-planar structure.
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Affiliation(s)
- J Pick
- Deutsches Zentrum für Luft- und Raumfahrt e.V., Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
- Leibniz Universität Hannover, Institut für Quantenoptik, Welfengarten 1, 30167 Hannover, Germany
| | - R Schwarz
- Deutsches Zentrum für Luft- und Raumfahrt e.V., Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
| | - J Kruse
- Deutsches Zentrum für Luft- und Raumfahrt e.V., Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
| | - C Lisdat
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - C Klempt
- Deutsches Zentrum für Luft- und Raumfahrt e.V., Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
- Leibniz Universität Hannover, Institut für Quantenoptik, Welfengarten 1, 30167 Hannover, Germany
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2
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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.
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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
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3
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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.
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Vovrosh J, Dragomir A, Stray B, Boddice D. Advances in Portable Atom Interferometry-Based Gravity Sensing. SENSORS (BASEL, SWITZERLAND) 2023; 23:7651. [PMID: 37688106 PMCID: PMC10490657 DOI: 10.3390/s23177651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/22/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023]
Abstract
Gravity sensing is a valuable technique used for several applications, including fundamental physics, civil engineering, metrology, geology, and resource exploration. While classical gravimeters have proven useful, they face limitations, such as mechanical wear on the test masses, resulting in drift, and limited measurement speeds, hindering their use for long-term monitoring, as well as the need to average out microseismic vibrations, limiting their speed of data acquisition. Emerging sensors based on atom interferometry for gravity measurements could offer promising solutions to these limitations, and are currently advancing towards portable devices for real-world applications. This article provides a brief state-of-the-art review of portable atom interferometry-based quantum sensors and provides a perspective on routes towards improved sensors.
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Affiliation(s)
- Jamie Vovrosh
- School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK; (J.V.)
- QinetiQ, Malvern Technology Centre, St. Andrews Road, Malvern, Worcestershire WR14 3PS, UK
| | - Andrei Dragomir
- Aquark Technologies, Abbey Park Industrial Estate, Romsey SO51 9AQ, UK
| | - Ben Stray
- School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK; (J.V.)
| | - Daniel Boddice
- School of Engineering, University of Birmingham, Birmingham B15 2TT, UK
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5
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Jin M, Zhang X, Liu X, Liang C, Liu J, Hu Z, Li K, Wang G, Yang J, Zhu L, Li G. A Centimeter-Scale Dielectric Metasurface for the Generation of Cold Atoms. NANO LETTERS 2023; 23:4008-4013. [PMID: 37098832 DOI: 10.1021/acs.nanolett.3c00791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The single-beam magneto-optical trap (MOT) based on the diffractive optical element offers a new route to develop compact cold atom sources. However, the optical efficiency in the previous single-beam MOT systems is usually low and unbalanced, which will affect the quality of the trapped atoms. To solve this issue, we developed a centimeter-scale dielectric metasurface optical chip with dynamic phase distributions, which was used to split a single incident laser beam into five separate ones with well-defined polarization states and uniform energy distributions. The measured diffraction efficiency of the metasurface is up to 47%. A single-beam MOT integrated with the metasurface optical chip was then used to trap the 87Rb atoms with numbers ∼1.4 × 108 and temperatures ∼7.0 μK. The proposed concept in this work may provide a promising solution for developing ultracompact cold atom sources.
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Affiliation(s)
- Mingke Jin
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xu Zhang
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China
- Interdisciplinary Center for Quantum Information, National University of Defense Technology, Changsha 410073, China
| | - Xuan Liu
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Institute of Laser Engineering, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China
| | - Changwen Liang
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China
- Interdisciplinary Center for Quantum Information, National University of Defense Technology, Changsha 410073, China
| | - Jixun Liu
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China
- Interdisciplinary Center for Quantum Information, National University of Defense Technology, Changsha 410073, China
| | - Zixian Hu
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Kingfai Li
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Guochao Wang
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China
- Interdisciplinary Center for Quantum Information, National University of Defense Technology, Changsha 410073, China
| | - Jun Yang
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China
- Interdisciplinary Center for Quantum Information, National University of Defense Technology, Changsha 410073, China
| | - Lingxiao Zhu
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China
- Interdisciplinary Center for Quantum Information, National University of Defense Technology, Changsha 410073, China
| | - Guixin Li
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
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6
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Bregazzi A, Janin P, Dyer S, McGilligan JP, Burrow O, Riis E, Uttamchandani D, Bauer R, Griffin PF. Cold-atom shaping with MEMS scanning mirrors. OPTICS LETTERS 2023; 48:37-40. [PMID: 36563364 DOI: 10.1364/ol.475353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
We demonstrate the integration of micro-electro-mechanical-systems (MEMS) scanning mirrors as active elements for the local optical pumping of ultra-cold atoms in a magneto-optical trap. A pair of MEMS mirrors steer a focused resonant beam through a cloud of trapped atoms shelved in the F = 1 ground-state of 87Rb for spatially selective fluorescence of the atom cloud. Two-dimensional control is demonstrated by forming geometrical patterns along the imaging axis of the cold atom ensemble. Such control of the atomic ensemble with a microfabricated mirror pair could find applications in single atom selection, local optical pumping, and arbitrary cloud shaping. This approach has significant potential for miniaturization and in creating portable control systems for quantum optic experiments.
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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.
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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.
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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
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9
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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.
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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
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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.
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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.
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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.
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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.
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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
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