Related papers: Cryogenic sapphire oscillator with exceptionally h…
We report on two ultrastable lasers each stabilized to independent silicon Fabry-P\'erot cavities operated at 124 K. The fractional frequency instability of each laser is completely determined by the fundamental thermal Brownian noise of…
We measure the power spectral density of frequency fluctuations in nanocontact spin torque oscillators over time scales up to 50 ms. We use a mixer to convert oscillator signals ranging from 10 GHz to 40 GHz into a band near 70 MHz before…
We present and analyze four frequency measurements designed to characterize the performance of an optical frequency reference based on spectral hole burning in \EuYSO. The first frequency comparison, between a single unperturbed spectral…
We present the design and realization of two reference cavities for ultra-stable lasers addressing narrow transitions in mixed-species (In+ / Yb+) Coulomb crystals. With a simple setup, we achieve a fractional frequency instability close to…
We report an investigation of laser frequency stabilization using a whispering gallery mode resonator that is temperature stabilized by a dual-mode technique. This dual-mode technique has yielded mode volume temperature instabilities at the…
Many-particle optical lattice clocks have the potential for unprecedented measurement precision and stability due to their low quantum projection noise. However, this potential has so far never been realized because clock stability has been…
We studied long duration flare observed with Nobeyama Radioheliograph at frequencies 17 and 34 GHz and with Ramaty High Energy Solar Spectroscopic Imager at 25-50 keV. We found that microwave and hard X-ray emission variation contain…
Accurate phase-locked 3:1 division of an optical frequency was achieved, by using a continuous-wave (cw) doubly resonant optical parametric oscillator. A fractional frequency stability of 2*10^(-17) of the division process has been achieved…
Dielectric resonators are key components for many microwave and millimetre wave applications, including high-Q filters and frequency-determining elements for precision frequency synthesis. These often depend on the quality of the dielectric…
We use two fiber-based femtosecond frequency combs and a low-noise carrier suppression phase detection system to characterize the optical to microwave synchronization achievable with such frequency divider systems. By applying specific…
We use a new technique to disseminate microwave reference signals along ordinary optical fiber. The fractional frequency resolution of a link of 86 km in length is 10-17 for a one day integration time, a resolution higher than the stability…
We have fabricated superconducting microwave resonators in a lumped element geometry using single crystal silicon dielectric parallel plate capacitors with C >2 pF. Aluminum devices with resonant frequencies between 4.0 and 6.5 GHz…
We re-analyzed two Rossi X-Ray Timing Explorer archival observations of the atoll source 4U 1820-30 in order to investigate the detailed time-frequency properties of the source during the intervals when a ~7 Hz QPO was detected by Wijnands…
To measure the spin period of the white dwarf in V1033 Cas with high precision, we performed extensive photometry. Observations were obtained over 34 nights in 2017. The total duration of the observations was 143 h. We found that the spin…
Towards a spin-based quantum microwave-optical photon transducer, we demonstrate a low-loss dielectric microwave resonator with an internal quality factor of $2.30\times10^4$ while accommodating optical apertures with a diameter of $8\,…
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 demonstrate the use of a fiber-based femtosecond laser locked onto an ultra-stable optical cavity to generate a low-noise microwave reference signal. Comparison with both a liquid Helium cryogenic sapphire oscillator (CSO) and a…
Experiments aimed at quantifying the interface between quantum and classical physics necessarily require a high degree of isolation from the environment: wavefunction collapse and quantum gravity effects at laboratory scales are predicted…
We stabilized the frequencies of two independent Nd:YAG lasers to two adjacent longitudinal modes of a high-finesse Fabry-P\'erot resonator and obtained a beat frequency instability of 6.3 mHz at an integration time of 40 s. Referred to a…
Improvements of the systematic uncertainty, frequency instability, and long-term reliability of the two caesium fountain primary frequency standards CSF1 and CSF2 at PTB (Physikalisch-Technische Bundesanstalt) are described. We have further…