Related papers: Interferometric length metrology for the dimension…
Large frame ring laser gyroscopes are top sensitivity inertial sensors able to measure absolute angular rotation rate below $\rm \mathbf{prad/s}$ in few seconds. The development of ring laser based on a simple mechanical structure, usually…
Ultra sensitive ring laser gyroscopes are regarded as potential detectors of the general relativistic frame-dragging effect due to the rotation of the Earth: the project name is GINGER (Gyroscopes IN GEneral Relativity), a ground-based…
Residual motion of the arm cavity mirrors is expected to prove one of the principal impediments to systematic lock acquisition in advanced gravitational-wave interferometers. We present a technique which overcomes this problem by employing…
The interrogation of an ultra-narrow clock transition of a single trapped ion for optical frequency metrology requires a laser stabilized to a couple of Hz per second with a linewidth of the same order of magnitude. Today, lasers in the…
An experimental method is developed for the robust frequency stabilization using a high-finesse cavity when the laser exhibits large intermittent frequency jumps. This is accomplished by applying an additional slow feedback signal from…
This work demonstrates that a middle size ring laser gyroscope (RLG) can be a very sensitive and robust instrument for rotational seismology, even if it operates in a quite noisy environment. The RLG has a square cavity, $1.60\times 1.60$…
A ring laser is defined by its perimeter, which directly enters the conversion factor between measured Sagnac frequency and the actual rotation rate. Large ring lasers employed in geodesy and fundamental physics require stability of the…
To obtain a high degree of long-term length stabilisation of an optical reference cavity, its free-spectral range is locked by means of an accurate and stable frequency synthesizer. The locking scheme is twofold: a laser is locked on the…
Using one arm of the Michelson interferometer and the power recycling mirror of the interferometric gravitational wave detector GEO600, we created a Fabry-Perot cavity with a length of 1200 m. The main purpose of this experiment was to…
Length and g-factor are fundamental parameters that characterize optical cavities. We developed a technique to measure these parameters in-situ by determining the frequency spacing between the resonances of fundamental and spatial modes of…
Large scale square ring laser gyros with a length of four meters on each side are approaching a sensitivity of 1x10^-11 rad/s/sqrt(Hz). This is about the regime required to measure the gravitomagnetic effect (Lense Thirring) of the Earth.…
We realize a Mach-Zehnder-type dual-atom-interferometer gyroscope with an interrogation arm of 40 cm length and the interference area up to 1.2 cm$^2$. The precise angular alignment of the large-scale separated Raman lasers is demonstrated…
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…
We present a passive, resonant, single-frequency gyroscope design that utilises polarisation modes of an optical cavity to readout rotation and generate a laser frequency discriminant. This design is notable for its simplicity, requiring no…
We use the three-cornered-hat method to evaluate the absolute frequency stabilities of three different ultrastable reference cavities, one of which has a vibration-insensitive design that does not even require vibration isolation. An Nd:YAG…
The development of an optical clock with ultimate accuracy and stability requires lasers with very narrow linewidth. We present two ultrastable laser systems based on 48 cm long Fabry-Perot cavities made of ULE glass in horizontal and…
We present two ultra-stable lasers based on two vibration insensitive cavity designs, one with vertical optical axis geometry, the other horizontal. Ultra-stable cavities are constructed with fused silica mirror substrates, shown to…
We present a fully active-controlled He-Ne ring laser gyroscope, operating in square cavity 1.35 m in side. The apparatus is designed to provide a very low mechanical and thermal drift of the ring cavity geometry and is conceived to be…
Large-scale high sensitivity laser gyroscopes have important applications for ground-based and space-based gravitational wave detection. We report on the development of a 3 m$\times$3 m heterolithic passive resonant gyroscope (HUST-1) which…
We propose a modulation-free optical frequency stabilization technique using an interferometric effect between transmitted and reflected lights from a reference cavity. The property of the reflected light brings robustness of the error…