A5012477215- Advanced Frequency and Time Standards
- Advanced Fiber Laser Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Quantum optics and atomic interactions
- Solid State Laser Technologies
- Spectroscopy and Laser Applications
- Scientific Measurement and Uncertainty Evaluation
- Cardiovascular Syncope and Autonomic Disorders
- Quantum Information and Cryptography
- Mechanical and Optical Resonators
- Photonic and Optical Devices
- Laser Design and Applications
- Orbital Angular Momentum in Optics
- Advanced Fiber Optic Sensors
- Advanced Measurement and Metrology Techniques
- Quantum Electrodynamics and Casimir Effect
- Advanced Optical Sensing Technologies
- Advanced MEMS and NEMS Technologies
- Optical Systems and Laser Technology
- Laser-Matter Interactions and Applications
- Optical Network Technologies
- Acoustic Wave Resonator Technologies
- Quantum Mechanics and Applications
- Photorefractive and Nonlinear Optics
National Institute of Advanced Industrial Science and Technology
2013-2024
Yokohama National University
2008-2024
Japan Science and Technology Agency
2010-2022
Massachusetts Institute of Technology
2019-2020
MIT-Harvard Center for Ultracold Atoms
2019-2020
The University of Tokyo
2009-2011
Tokyo Institute of Technology
2002-2010
Storage and retrieval of a squeezed vacuum was successfully demonstrated using electromagnetically induced transparency. The pulse having temporal width 930 ns incident on the laser cooled $^{87}\mathrm{Rb}$ atoms with an intense control light in coherent state. When slowed spatially compressed cold atoms, switched off. After $3\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ storage, again, retrieved, as confirmed time-domain homodyne method.
We report on the direct conversion of laser-cooled $^{41}\mathrm{K}$ and $^{87}\mathrm{Rb}$ atoms into ultracold $^{41}\mathrm{K}^{87}\mathrm{Rb}$ molecules in rovibrational ground state via photoassociation followed by stimulated Raman adiabatic passage. High-resolution spectroscopy based coherent transfer revealed hyperfine structure weakly bound an unexplored region. Our results show that a rovibrationally pure sample ground-state is achieved all-optical association atoms, opening...
Spin squeezing can improve atomic precision measurements beyond the standard quantum limit (SQL), and unitary spin is essential for improving clocks. We report substantial nearly in $^{171}$Yb, an optical lattice clock atom. The collective nuclear of $\sim 10^3$ atoms squeezed by cavity feedback, using light detuned from system's resonances to attain unitarity. observed gain over SQL limited state readout 6.5(4) dB, while generated states offer a 12.9(6) curvature Bloch sphere. Using within...
We search for ultralight scalar dark matter candidates that induce oscillations of the fine structure constant, electron and quark masses, quantum chromodynamics energy scale with frequency comparison data between a $^{171}\mathrm{Yb}$ optical lattice clock $^{133}\mathrm{Cs}$ fountain microwave span 298 days an uptime 15.4%. New limits on couplings to electrons gluons in mass range from ${10}^{\ensuremath{-}22}$ ${10}^{\ensuremath{-}20}\text{ }\text{ }\mathrm{eV}/{c}^{2}$ are set, assuming...
The Rayleigh-Taylor instability at the interface in an immiscible two-component Bose-Einstein condensate is investigated using mean field and Bogoliubov theories. fingers are found to grow from mushroom patterns formed. Quantized vortex rings lines then generated around mushrooms. mushroom-pattern formation can be observed a trapped system.
The squeezed vacuum resonant on the $^{87}\mathrm{Rb}$ ${D}_{1}$ line (probe light) was injected into an optically dense rubidium gas cell with a coherent light (control light). output probe maintained its quadrature squeezing within transparency window caused by electromagnetically induced (EIT). results reported here are first realization of EIT in full quantum regime.
We demonstrate an improved absolute frequency measurement of the 1S0–3P0 clock transition at 578 nm in 171Yb atoms a one-dimensional optical lattice. The laser linewidth is reduced to ≈2 Hz by phase-locking ultrastable neodymium-doped yttrium aluminum garnet (Nd:YAG) 1064 through comb with intracavity electrooptic modulator achieve high servo bandwidth. determined as 518 295 836 590 863.1(2.0) relative SI second, and will be reported International Committee for Weights Measures.
Abstract An Er:fiber comb based on a mode-locked laser was developed, employing semiconductor saturable absorber mirror and an intra-cavity electro-optic modulator. The carrier-envelope offset frequency of the phase-locked with servo bandwidth 60 kHz using divide-by-10 divider. Subsequently, to iodine-stabilized Nd:YAG 550 kHz, without necessity Furthermore, relative linewidth developed evaluated by comparing it another optical comb, confirming that less than 1 Hz.
Abstract We report improved absolute frequency measurement of the 1 S 0 - 3 P transition 171 Yb at National Metrology Institute Japan (NMIJ) by comparing optical lattice clock NMIJ-Yb1 with 13 Cs primary standards via International Atomic Time from August 2021 to May 2023. The measured is 518 295 836 590 863.62(10) Hz a fractional uncertainty 1.9 × 10 -16 , in good agreement recommended as secondary representation second. This 2.6 times lower than our previous uncertainty, and slightly any...
We propose a novel, high-performance, and practical laser source system for optical clocks. The linewidth of fiber-based frequency comb is reduced by phase locking mode to an ultrastable master at 1064 nm with broad servo bandwidth. A slave 578 successively locked bandwidth without any pre-stabilization. Laser characteristics such as spectral stability are transferred the 578-nm from 1064-nm laser. Using laser, we have succeeded in observing clock transition (171)Yb atoms confined lattice...
The frequency ratio of the 1S0(F=1/2)-3P0(F=1/2) clock transition in 171Yb and 1S0(F=9/2)-3P0(F=9/2) 87Sr is measured by an optical-optical direct link between two optical lattice clocks. We determined (\nu_{Yb}/\nu_{Sr}) to be 1.207 507 039 343 340 4(18) with a fractional uncertainty 1.5x10^{-15}. measurement smaller than that obtained from absolute measurements using International Atomic Time (TAI) link. agrees well derived results at NIST JILA, Boulder, CO their Cs-fountain clock. Our...
We report the generation of a continuous-wave squeezed vacuum resonant on Rb D1 line (795 nm) using periodically poled KTiOPO4 (PPKTP) crystals. With frequency doubler and an optical parametric oscillator based PPKTP crystals, we observed squeezing level -2.75+/-0.14 dB antisqueezing +7.00+/-0.13 dB. This system could be utilized for demonstrating storage retrieval vacuum, which is important ultraprecise measurement atomic spins as well quantum information processing.
We have succeeded in observing ultraslow propagation of squeezed vacuum pulses with electromagnetically induced transparency. Squeezed (probe lights) were incident on a laser cooled 87Rb gas together an intense coherent light (control light). A homodyne method sensitive to the state was employed for detecting probe pulse passing through gas. delay 3.1us observed having temporal width 10 us.
We review our experimental progress toward achieving the production of quantum degenerate bosonic polar molecules, 41K87Rb. Our primary goal is to transfer Feshbach molecules into absolute ground state via stimulated Raman adiabatic passage (STIRAP). have achieved a dual-species Bose–Einstein condensate 41K and 87Rb in magnetic trap, which consists NK=1.4×104 potassium atoms NRb=3.5×104 rubidium atoms. An optimum optical transition for STIRAP being identified by separate experiment based on...
We have developed a Fabry–Pérot etalon with an ultralow expansion ceramic spacer and investigated the thermal properties of ceramic. found that cavity has “zero crossing temperature” at room temperature where coefficient crosses zero. The sensitivity to change is about five times greater than (ULE) glass around zero cross temperature. Nevertheless, owing high specific rigidity relatively low temperature, should be attractive material for long optical cavities can reduce effect noise relatively.
We performed spectroscopic observations of the 698-nm clock transition in 87Sr confined an optical lattice using a laser linewidth transfer technique. A narrow-linewidth interrogating was prepared by transferring master (1064 nm) to that slave (698 with high-speed controllable fiber-based frequency comb. The Fourier-limited spectrum then observed for 80-ms pulse. determined absolute 5s2 1S0–5s5p 3P0 is 429 228 004 229 872.0 (1.6) Hz referenced SI second.
Precision spectroscopy contributed significantly to the development of quantum mechanics in its early stages. In twenty-first century, precision has played an important role several fields, including fundamental physics, measurement, environmental monitoring, and medical diagnostics. An optical frequency comb is indispensable determining axis it useful as a light source for spectroscopy. Dual-comb uses two combs with slightly different repetition rates potential surpass conventional...
We report on the achievement of a reduced time difference in scale with respect to Coordinated Universal Time (UTC) by steering hydrogen-maser-based near-continuously operating optical lattice clock. The is generated postprocessing analysis for 230 days using hydrogen maser its fractional frequency stability limited flicker floor $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}$ and an $\mathrm{Yb}$ clock operated uptime 81.6%. During 230-day period, root-mean-square our UTC 0.52...
A narrow linewidth diode laser system at 689 nm is realized by phase-locking an extended cavity to one tooth of a optical frequency comb. The comb phase-locked 1064 nm, which stabilized high-finesse cavity. We demonstrate the magneto-optical trapping Sr using intercombination transition with developed system.
We demonstrate a compact iodine-stabilized laser operating at 531 nm using coin-sized light source consisting of 1062-nm distributed-feedback diode and frequency-doubling element. A hyperfine transition molecular iodine is observed the with saturated absorption spectroscopy. The frequency stabilized to achieves stability 10(-12) level. absolute a(1) component R(36)32 - 0 determined as 564074632419(8) kHz relative uncertainty 1.4×10(-11). can be used for various applications including...
We performed an absolute frequency measurement of the $^1S_{0}$-$^3P_{0}$ transition in $^{87}$Sr with a fractional uncertainty $1.2 \times 10^{-15}$, which is less than one third that our previous measurement. A caesium fountain atomic clock was used as transfer oscillator to reduce link between strontium optical lattice and SI second. The value 429 228 004 229 873.56(49) Hz.
We report absolute frequency measurements of 81 hyperfine components the rovibrational transitions molecular iodine at 578 nm using second harmonic generation an 1156-nm external-cavity diode laser and a fiber-based optical comb. The relative uncertainties measured frequencies are typically $1.4\times10^{-11}$. Accurate constants four obtained by fitting splittings to four-term effective Hamiltonian including electric quadrupole, spin-rotation, tensor spin-spin, scalar spin-spin...
Abstract We performed Doppler-free spectroscopy on the P(40)52-0 and P(52)53-0 lines of molecular iodine ( 127 I 2 ) near 1 S 0 - 3 P metastable transition Yb at 507 nm. The frequency instability an external-cavity diode laser locked to observed hyperfine transitions reached a level below 1.0 <?CDATA $\times $?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>×</mml:mo> </mml:math> 10 −12 , average time $\tau <mml:mi>τ</mml:mi> measurement >10 s....
Abstract The recently concluded collaborative European project “Robust optical clocks for international timescales” (ROCIT) tackled some of the key challenges on roadmap towards a redefinition SI second. This paper gives an overview progress made improving robustness and automation verifying their uncertainty budgets through coordinated comparison campaigns. It also presents work incorporation into time scales, covering both use to steer local physical scales evaluations hydrogen masers...