Related papers: Making optical atomic clocks more stable with $10^…
Optical atomic clocks are poised to redefine the SI second, thanks to stability and accuracy more than one hundred times better than the current microwave atomic clock standard. However, the best optical clocks have not seen their…
Optical clock network requires the establishment of optical frequency transmission link between multiple optical clocks, utilizing narrow linewidth lasers. Despite achieving link noise levels of 10${^{-20}}$, the final accuracy is limited…
We present a transportable ultra-stable clock laser system based on a Fabry-P\'erot cavity with crystalline Al$_{0.92}$Ga$_{0.08}$As/GaAs mirror coatings, fused silica (FS) mirror substrates and a 20~cm-long ultra-low expansion…
The stability of an optical atomic clock is a critical figure of merit for almost all clock applications. To this end, much optical atomic clock research has focused on reducing clock instability by increasing the atom number, lengthening…
Extra-laboratory atomic clocks are necessary for a wide array of applications (e.g. satellite-based navigation and communication). Building upon existing vapor cell and laser technologies, we describe an optical atomic clock, designed…
Time and frequency are the most accurately measurable quantities, providing foundations for science and modern technologies. The accuracy relies on the SI (Syst\'eme International) second that refers to Cs microwave clocks with fractional…
Currently, the most accurate and stable clocks use optical interrogation of either a single ion or an ensemble of neutral atoms confined in an optical lattice. Here, we demonstrate a new optical clock system based on an array of…
A caesium fountain clock is operated utilizing a microwave oscillator that derives its frequency stability from a stable laser by means of a fiber-laser femtosecond frequency comb. This oscillator is based on the technology developed for…
We report in detail the design process and performance of an auto-locking ultra-stable laser with sub-hertz linewidth at the first time. The laser frequency is automatically stabilized to an optical reference cavity with a home-made…
Despite being a canonical example of quantum mechanical perturbation theory, as well as one of the earliest observed spectroscopic shifts, the Stark effect contributes the largest source of uncertainty in a modern optical atomic clock…
Recent progress in optical lattice clocks requires unprecedented precision in controlling systematic uncertainties at $10^{-18}$ level. Tuning of nonlinear light shifts is shown to reduce lattice-induced clock shift for wide range of…
Optical clocks benefit from tight atomic confinement enabling extended interrogation times as well as Doppler- and recoil-free operation. However, these benefits come at the cost of frequency shifts that, if not properly controlled, may…
Frequency-stable lasers enable high-fidelity quantum state manipulation, which forms the basis of optical atomic clocks, quantum sensing, and quantum computation. Performing state manipulations at increasingly high speeds requires attention…
Lasers with hertz-level linewidths on timescales up to seconds are critical for precision metrology, timekeeping, and manipulation of quantum systems. Such frequency stability typically relies on bulk-optic lasers and reference cavities,…
An optical atomic clock scheme is developed that utilizes two lasers to establish coherent coupling between the $5s^2 \phantom{}^1S_0$ ground state of $^{88}$Sr and the first excited state, $5s5p \phantom{}^3P_0$. The coupling is mediated…
Ultra-stable lasers and optical frequency combs have been the enabling technologies for the tremendous progress of precise optical spectroscopy in the last ten years. To improve laser frequency stabilization beyond the thermal-noise…
We demonstrated transferring the stability of one highly stable clock laser operating at 729 nm to another less stable laser operating at 698 nm. The two different wavelengths were bridged using an optical frequency comb. The improved…
The passage of time is tracked by counting oscillations of a frequency reference, such as Earth's revolutions or swings of a pendulum. By referencing atomic transitions, frequency (and thus time) can be measured more precisely than any…
Existing optical lattice clocks demonstrate a high level of performance, but they remain complex experimental devices. In order to address a wider range of applications including those requiring transportable devices, it will be necessary…
We present a compact atomic clock interrogating ultracold 87Rb magnetically trapped on an atom chip. Very long coherence times sustained by spin self-rephasing allow us to interrogate the atomic transition with 85% contrast at 5 s Ramsey…