A5049767118- Advanced Frequency and Time Standards
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Quantum optics and atomic interactions
- Cardiovascular Syncope and Autonomic Disorders
- Scientific Measurement and Uncertainty Evaluation
- Atomic and Molecular Physics
- Advanced Fiber Laser Technologies
- Laser Design and Applications
- Dark Matter and Cosmic Phenomena
- Spectroscopy and Laser Applications
- Mass Spectrometry Techniques and Applications
- Electrochemical Analysis and Applications
- Laser-Matter Interactions and Applications
- Quantum Information and Cryptography
- Photonic and Optical Devices
- Vacuum and Plasma Arcs
- Mechanical and Optical Resonators
- Particle accelerators and beam dynamics
- Ion-surface interactions and analysis
- Advanced Materials Characterization Techniques
- Plasma Diagnostics and Applications
- Quantum Mechanics and Applications
University of Amsterdam
2021-2025
University of Copenhagen
2015-2024
British Occupational Health Research Foundation
2024
National Institute of Standards and Technology
2018-2021
GSI Helmholtz Centre for Heavy Ion Research
2008
The pursuit of ever more precise measures time and frequency motivates redefinition the second in terms an optical atomic transition.To ensure continuity with current definition, based on microwave hyperfine transition 133 Cs, it is necessary to measure absolute candidate standards relative primary cesium references.Armed independent measurements, a stringent test clocks can be made by comparing ratios measurements against measured via direct comparison.Here we 1 S 0 → 3 P 171 Yb using...
Highly stable laser sources based on narrow atomic transitions provide a promising platform for direct generation of and accurate optical frequencies. Here we investigate simple system operating in the high-temperature regime cold atoms. The interaction between thermal ensemble $^{88}$Sr at mK temperatures medium-finesse cavity produces strong collective coupling facilitates high coherence which causes lasing dipole forbidden $^1$S$_0 \leftrightarrow ^3$P$_1$ transition. We experimentally...
Abstract When an inverted ensemble of atoms is tightly packed on the scale its emission wavelength or when are collectively strongly coupled to a single cavity mode, their dipoles will align and decay rapidly via superradiant burst. However, spread-out dipole phase distribution theory predicts required minimum threshold atomic excitation for superradiance occur. Here we experimentally confirm this predicted narrow optical transition exciting transversely show how take advantage resulting...
Continuous superradiance using a narrow optical transition has the potential to improve short-term stability of state-of-the-art clocks. Even though pulsed superradiant emission on <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>mHz</a:mi></a:math> linewidth clock been shown, true continuous operation, without Fourier limitation, turned out be extremely challenging. The trade-off between maintaining high atomic flux while minimizing decoherence effects presents significant...
Highly accurate and precise timekeeping supports many technologies for $e.g.$ navigation telecommunication, as well fundamental science. Nowadays optical clocks are far more stable than older microwave clocks, yet cannot be operated continuously. This study presents a hybrid microwave-optical time scale, in which the clock runs intermittently, importantly explores improving this system aside from its clock. The offers world-record accuracy, maintaining fractional frequency uncertainty of...
We study the non-linear interaction of a cold sample strontium-88 atoms coupled to single mode low finesse optical cavity in so-called bad limit and investigate implications for applications laser stabilization. The are probed on weak inter-combination line $\lvert 5s^{2} \, ^1 \textrm{S}_0 \rangle \,-\, \lvert 5s5p ^3 \textrm{P}_1 \rangle$ at 689 nm strongly saturated regime. Our measured observables include atomic induced phase shift absorption light field transmitted through represented...
Hybrid systems of cold atoms and optical cavities are promising for increasing the stability laser oscillators used in quantum metrology atomic clocks. In this paper we map out atom-cavity dynamics such a system demonstrate limitations as well robustness approach. We investigate phase response an ensemble $^{88}\mathrm{Sr}$ inside cavity use error signal frequency stabilization. With realize regime where high shift limits dynamical locking range. The limitation is caused by transfer function...
We demonstrate the absence of a dc Stark shift in an ytterbium optical lattice clock. Stray electric fields are suppressed through introduction in-vacuum Faraday shield. Still, effectiveness shielding must be experimentally assessed. Such diagnostics accomplished by applying high voltage to six electrodes, which grounded normal operation form part Our measurements place constraint on at 10^{-20} level, units clock frequency. Moreover, we discuss potential source error strategies precisely...
Atomic clocks occupy a unique position in measurement science, exhibiting higher accuracy than any other standard and underpinning six out of seven base units the SI system. By exploiting resonance frequencies, optical atomic now achieve greater stability lower frequency uncertainty existing primary standards. Here, we report ratios $^{27}$Al$^+$, $^{171}$Yb $^{87}$Sr Boulder, Colorado, measured across an network spanned by both fiber free-space links. These have been evaluated with...
Atoms coupled to cavities provide an exciting playground for the study of fundamental interactions atoms mediated through a common channel. Many applications cavity QED and cold-atom experiments more broadly, suffer from limitations caused by transient nature atomic loading cycle. The development continuous operation schemes is necessary push these systems next level performance. Here we present machine designed produce flux collimated that traverse optical cavity. atom-light interaction...
Lasing in the bad cavity regime has promising applications precision metrology due to reduced sensitivity noise. Here we investigate spectral properties and phase behavior of pulsed lasing on $^1$S$_0 - ^3$P$_1$ line $^{88}$Sr a mK thermal ensemble, as first described arxiv:1903.12593. The system operates where Doppler-broadened atomic transition linewidth is several times larger than linewidth. We find that by detuning resonance, influence noise peak frequency can be eliminated order...
This paper describes the recent National Institute of Standards and Technology (NIST) work on incorporating an optical clock into a time scale. We simulate scale composed continuously operating commercial hydrogen masers frequency standard that does not operate as clock. The simulations indicate to achieve same performance Cs-fountain scale, it is necessary run 12 minutes per half day, or 1 hour 4 hours 2.33 week. Following simulations, Yb at NIST was frequently operated during periods 2017...
The prospects of superradiant lasing on the 7.5 kHz wide $^1$S$_0$-$^3$P$_1$ transition in $^{88}$Sr is explored by using numerical simulations two systems based realistic experimental numbers. One system uses idea demonstrating continuous superradiance a simple, hot atom beam with high flux, and other ultra-cold atoms dipole guide. We find that achieves above flux $2.5 \times 10^{12}$ atoms/s. It capable outputting hundreds nW suppressing cavity noise factor 20-30. second order Doppler...
Ultra stable frequency references such as the ones used in optical atomic clocks and for quantum metrology may be obtained by stabilizing a laser to an cavity that is over time. State-of-the-art are constructed this way, but their stabilities currently limited thermally induced length fluctuations reference cavity. Several alternative approaches using potential discriminating of highly forbidden narrow transitions have been proposed in, e.g., [1] [2]. In proceeding we will present some...
Vacuum arc ion sources, Penning and filament driven multicusp sources are used for the production of high current beams a variety metallic gaseous ions at GSI accelerator facility. For operation, have to provide stable beam over long period time with an energy 2.2 keV/u maximum mass charge ratio 65. The status operation injector is presented here giving outline on important source data, such as current, spectrum, transversal emittance, life time, duty factor, transmission along low transport section.
We use frequency comb-based optical two-way time-frequency transfer (O-TWTFT) to measure the ratio of state-of-the-art ytterbium and strontium atomic clocks separated by a 1.5 km open-air link. Our free-space measurement is compared simultaneous acquired via noise-cancelled fiber Despite non-stationary, ps-level time-of-flight variations in link, measurements obtained from two links, averaged over 30.5 hours across six days, agree $6\times10^{-19}$, showing that O-TWTFT can support clock...
The pursuit of ever more precise measures time and frequency is likely to lead the eventual redefinition second in terms an optical atomic transition. To ensure continuity with current definition, based on a microwave transition between hyperfine levels ground-state $^{133}$Cs, it necessary measure absolute candidate standards, which done by comparing against primary cesium reference. A key verification this process can be achieved performing loop closure$-$comparing ratios derived from...
Atoms coupled to cavities provide an exciting playground for the study of fundamental interactions atoms mediated through a common channel. Many applications cavity-QED and cold-atom experiments more broadly, suffer from limitations caused by transient nature atomic loading cycle. The development continuous operation schemes is necessary push these systems next level performance. Here we present machine designed produce flux collimated that traverse optical cavity. atom-light interaction...
Continuous superradiance using a narrow optical transition has the potential to improve short-term stability of state-of-the-art clocks. Even though pulsed superradiant emission on mHz linewidth clock been shown, true continuous operation, without Fourier limitation, turned out be extremely challenging. The trade-off between maintaining high atomic flux while minimizing decoherence effects presents significant obstacle. Here, we discuss design machine that could overcome this problem by...
When an inverted ensemble of atoms is tightly packed on the scale its emission wavelength or when are collectively strongly coupled to a single cavity mode, their dipoles will align and decay rapidly via superradiant burst. However, spread-out dipole phase distribution theory predicts required minimum threshold atomic excitation for superradiance occur. Here we experimentally confirm this predicted narrow optical transition exciting transversely show how take advantage resulting sub-...
Cavity enhanced spectroscopy on ultra-narrow transitions in atoms and molecules is a promising tool for frequency stabilization of clock lasers. However, the small beam waist typical cavity can effectively reduce number system or introduce transit time broadening less controlled molecular systems. We present design with an internal telescope optimized to increase from about 0:5 mm 5 while still maintaining convenient range tuning parameters. Its usefulness three separate spectroscopic...
The development of simple and reliable high stability clock lasers is great importance for future state-of-the-art optical clocks [1]-[5] transportable [6], [7]. Further with better has so far been hindered by thermal noise in the reference cavity used laser stabilization conventional approaches improvements may be technically challenging. It proposed [8]-[11] to improve reduce complexity frequency exploiting QED systems consisting atoms a narrow transition coupled single mode an cavity....
We describe ytterbium optical lattice clocks under development at NIST. This includes the characterization of frequency stability and uncertainty, as well measurements between two independent clocks, 10−18level. also report on ratio with other