Related papers: An active fiber sensor for mirror vibration metrol…
We have developed a system for tapered fiber measurements of optomechanical resonators inside a dilution refrigerator, which is compatible with both on- and off-chip devices. Our apparatus features full three-dimensional control of the…
In this paper, we propose a novel non-contact vibration measurement system that is competent in estimating linear and/or rotational motions of machine parts. The technique combines microwave radar, standard camera, and optical strobe to…
We measure molecular vibrations with femtometer precision using time-resolved x-ray absorption spectroscopy. For a demonstration, a Raman process excites the A$_{1g}$ mode in gas-phase SF$_6$ molecules with an amplitude of $\approx50$ fm,…
Integrated optics are used to achieve astronomical interferometry inside robust and compact materials, improving the instruments stability and sensitivity. In order to perform differential phase measurements at the H$\alpha$ line (656.3 nm)…
Virgo is a kilometer-length interferometer for gravitational waves detection located near Pisa. Its first science run, VSR1, occured from May to October 2007. The aims of the calibration are to measure the detector sensitivity and to…
Beginning in Fall 2018, the VERITAS high energy gamma-ray observatory (Amado, AZ) was upgraded to enable Stellar Intensity Interferometry (SII) observations during bright moon conditions. The system potentially allows VERITAS to spatially…
A suspension-point interferometer (SPI) is an auxiliary interferometer for active vibration isolation, implemented at the suspension points of the mirrors of an interferometric gravitational wave detector. We constructed a prototype…
A spherical Fabry-Perot interferometer with adjustable mirror spacing is used to produce interference fringes with frequency separation (c/2L)/N, N=2-15. The conditions for observation of these fringes are derived from the consideration of…
We report on the measurements of tilt noise performed at the Virgo site with a ring laser gyroscope. The apparatus is a He-Ne laser operating in a square cavity mounted on a vertical plane perpendicular to the north-south arm of the…
Resonance modes are intrinsic characteristics of objects when excited at those frequencies. Probing the resonance signatures can reveal useful information about material composition, geometry, presence of defects, and other characteristics…
Predictions and measurements of a multimode waveguide interferometer operating in a fibre coupled, ``dual-mode'' regime are reported. With a 1.32 micrometer source, a complete switching cycle of the output beam is produced by a 10.0…
We present an absolute distance measurement interferometer based on a two wavelength interferometer and a variable synthetic wavelength technique. The wavelength scanning range was 12 GHz, realized with a phase accuracy of 1.0 m{\lambda} by…
The possibility of measuring the second order correlation function of the gravitational waves detectors' currents or photonumbers, and the observation of the gravitational signals by using a spectrum analyzer is discussed. The method is…
We report on the active stabilization of a Michelson interferometer at an arbitrary phase angle with a precision better than one degree at $\lambda = 632.8$ nm, which corresponds to an optical path difference between the two arms of less…
In this paper, we report high-precision absolute distance and vibration measurements performed with frequency scanned interferometry. Absolute distance was determined by counting the interference fringes produced while scanning the laser…
A high sensitivity force sensor based on dielectric microspheres in vacuum, optically trapped by a single, upward-propagating laser beam, is described. Off-axis parabolic mirrors are used both to focus the 1064~nm trapping beam and to…
Conventional techniques that measure rapid time variations are inefficient or inadequate to discover and observe rapidly pulsating astronomical sources. It is therefore conceivable that there exist some classes of objects pulsating with…
We improve the calculations of the elastic motion induced by the dark matter hits on the surface of the mirror equipped with the interferometer for gravitational waves detection. We focus on the discovery potential of such a dark matter…
Gravitational wave detectors such as KAGRA, a 3-km long underground laser interferometer in Japan, require elaborate passive and active seismic isolation of their mirrors. With the aim of detecting passing gravitational waves that create a…
A novel and efficient method for fiber transfer delay measurement is demonstrated. Fiber transfer delay measurement in time domain is converted into the frequency measurement of the modulation signal in frequency domain, accompany with a…