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Search Publications

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Displaying 826 - 850 of 2581

Laser-cooling in a chip-scale platform

August 3, 2020
Author(s)
James P. McGilligan, Kaitlin R. Moore, Argyrios Dellis, Gabriela Martinez, E. de Clercq, Paul Griffin, A S. Arnold, E Riis, Rodolphe Boudot, John Kitching
Chip-scale atomic devices built around micro-fabricated alkali vapor cells are at the forefront of compact metrology and atomic sensors. We demonstrate a micro-fabricated vapor cell that is actively pumped to ultra-high-vacuum (UHV) to achieve laser

Does Cosmological Evolution Select for Technology?

July 30, 2020
Author(s)
Jeff Shainline
Fine tuning of the parameters defining the physics of our universe has been proposed to result from the natural selection of universes capable of prolific reproduction. This cosmic reproduction may occur through singularities, and it has been argued that

Understanding Photovoltaic Energy Losses under Indoor Lighting Conditions

July 28, 2020
Author(s)
Behrang H. Hamadani
The external luminescence quantum yield as a function of the solar cell current density when exposed to low indoor light was estimated based on absolute electroluminescence measurements and a self-consistent use of the electro-optical reciprocity

Nanophotonic tantala waveguides for supercontinuum generation pumped at 1560 nm

July 22, 2020
Author(s)
Kieran F. LaMee, David Carlson, Zachary Newman, Su P. Yu, Scott Papp
We experimentally demonstrate efficient and broadband supercontinuum generation in nonlinear tantala (Ta2O5) waveguides using a 1560 nm femtosecond seed laser. With incident pulse energies as low as 100 pJ, we create spectra spanning up to 1.6 octaves

Electromagnetics for Quantitative Magnetic Resonance Imaging

July 20, 2020
Author(s)
Stephen E. Russek, Karl F. Stupic, Joshua R. Biller, Michael A. Boss, Kathryn E. Keenan, Elizabeth Mirowski
Magnetic Resonance Imaging (MRI) is based on radio frequency (RF) interrogation of the human body at frequencies between 40 MHz to 300 MHz. An RF transmitter excites proton spin precession and then, in a manner analogous to an RF ID tag, the proton’s

3D printed optical concentrators for LED arrays

July 19, 2020
Author(s)
Behrang H. Hamadani, Jonathan E. Seppala, Clarence J. Zarobila
Additive manufacturing methods based on photopolymerization offer a great potential for fabrication of high quality, highly transparent optical components. One appropriate use of these technologies is related to fabrication of parts that can be used in

Optical Frequency Combs: Coherently Uniting the Electromagnetic Spectrum

July 17, 2020
Author(s)
Scott Diddams, Kerry J. Vahala, Thomas Udem
Optical frequency combs were introduced around 20 years ago as a laser technology that could synthesize and count the ultrafast rate of the oscillating cycles of light. Functioning in a manner analogous to a clockwork of gears, the frequency comb phase

Coherent optical nano-tweezers for ultra-cold atoms

July 7, 2020
Author(s)
Przemek Bienias, Sarthak Subhankar, Yang Wang, Tsz-Chun Tsui, Fred Jendrzejewski, Tobias Tiecke, Gediminas Juzeliunas, Liang Jiang, Steven Rolston, James V. Porto, Alexey Gorshkov

Reversible Room-Temperature Fluoride-Ion Insertion in a Tunnel-Structured Transition Metal Oxide Host

July 6, 2020
Author(s)
Cherno Jaye, Wasif Zaheer, Justin L. Andrews, Forrest P. Hyler, Conan Weiland, David A. Shapiro, Jinghua Guo, Jesus M. Velazquez, Sarbajit Banerjee, Abhishek Parija, Daniel Fischer
An energy storage paradigm orthogonal to conventional Li-ion battery chemistries can be conceptualized by employing anions as the primary charge carriers. F-ion conversion chemistries show promise but have limited cyclability as a result of the significant

Comparison of the multi-national SIM time scale to UTC and UTCr

July 1, 2020
Author(s)
J. M. Lopez, Michael Lombardi, E. de Carlos, N. Munoz, C. Ortiz, M. Gertsvolf, R. de Carvalho, R. Solis
The Sistema Interamericano de Metrologia (SIM) is one of the world's five major Regional Metrology Organizations (RMO's) recognized by the International Committee for Weights and Measures (CIPM). With the goal of allowing SIM National Metrology Institutes

Mid-infrared frequency combs at 10 GHz

June 29, 2020
Author(s)
Abijith S. Kowligy, David Carlson, Daniel D. Hickstein, Henry R. Timmers, Alexander Lind, Scott Papp, Scott Diddams
We demonstrate 10 GHz mid-infrared frequency combs spanning 3-5 μm and 7-11 μm that are generated with few-cycle electro-optic pulses and intrapulse difference-frequency generation.

Thermal Decoherence and Laser Cooling of Kerr-microresonator Solitons

June 22, 2020
Author(s)
Tara E. Drake, Jordan Stone, Travis Briles, Scott Papp
Thermal noise is ubiquitous in microscopic systems and high-precision measurements. The control of thermal noise would reveal quantum regimes1 and enable fundamental physics searches2 . Recently, nonlinearity in microresonators has enabled laser devices

Measurements of the Linear Polarization of Satellite Transitions from Li- and Be- like Ar Ions

June 18, 2020
Author(s)
Amy Gall, Dipti Goyal, Sean W. Buechele, Samuel C. Sanders, Roshani Silwal, Csilla Szabo-Foster, N Brickhouse, Yuri Ralchenko, Endre A. Takacs
Non-thermal electron distributions, such as beams of electrons, are found in many laboratory and astrophysical plasma sources and can produce anisotropic and polarized emission. Theories used to model the emission require sublevel specific analysis, which

Complete collision data set for electrons scattering on molecular hydrogen and its isotopologues: I. Fully vibrationally-resolved electronic excitation of H2(X 1O+g ).

June 16, 2020
Author(s)
Liam H. Scarlett, D Fursa, Mark C. Zammit, Igor Bray, Yuri Ralchenko, Kayla D. Davie
We present a comprehensive set of vibrationally-resolved cross sections for electron-impact electronic excitation of molecular hydrogen suitable for implementation in collisional-radiative models. The adiabatic-nuclei molecular convergent close-coupling

Determination of the isotopic change in nuclear charge radius from extreme-ultraviolet spectroscopy of highly charged ions of Xe

June 16, 2020
Author(s)
Yuri Ralchenko, Roshani Silwal, A. Lapierre, John Gillaspy, Joan M. Dreiling, S A. Blundell, Dipti Goyal, A. Borovik, Jr., G Gwinner, A.C.C. Villari, Endre Takacs
The electron beam ion trap (EBIT) at the National Institute of Standards and Technology was employed to measure the isotopic shift of the Na-like D 3s 2S1=2 3p 2P1=2;3=2, Mg-like 3s2 1S0 3s3p 1P1, Mg-like 3s2 1S0 3s3p 3P1, Al-like 3s23p 2P1=2 3s23p 2P3=2

Generating GHZ states with squeezing and post-selection

June 1, 2020
Author(s)
Byron Alexander, Hermann Uys, John Bollinger
Many quantum state preparation methods rely on a combination of dissipative quantum state initialization, followed by unitary evolution to a desired target state. Here we demonstrate the usefulness of quantum measurement as an additional tool for quantum

Comparison of Open and Solid Falling Retroreflector Gravimeters

May 29, 2020
Author(s)
Neil Ashby, Derek Van Westrum
We study whether the optical properties of a solid glass retroreflector influence the value of the acceleration of gravity $g$ determined by dropping both solid and open retroreflectors in an absolute ballistic gravimeter. The retroreflectors have
Displaying 826 - 850 of 2581
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