maddalena mantovani
(EGO)
24/05/2016, 18:00
poster
A novel simple Faraday isolator system allowing for a good isolation factor and low throughput losses, under high vacuum and exposed to a source of medium-near infra-red continuous laser radiation is presented. An isolation factor as high as 40dB and losses lower than 3% can be reached in the presented set-up. The mechanical and optical configuration is detailed and the performances achieved...
Mr
Kunihiko Hasegawa
(Institute for Cosmic Ray Research, the University of Tokyo,)
24/05/2016, 18:00
poster
The cryogenic sapphire mirrors in KAGRA are expected to suffer from many contaminations due to dust adhesion and gas molecules. The contamination due to dust particles is occurred during their installation process. The cryogenic contamination effect has not been studied correctly in the actual KAGRA cryostat system. To estimate these possible total contaminations in the cryostat, we firstly...
Prof.
CS Unnikrishnan
(Tata Institute of Fundamental Research, Mumbai, India)
24/05/2016, 18:00
poster
All practical proposals to detect low frequency gravitational waves in the frequency range 0.001 Hz to 0.1 Hz involve multi-satellite spaceborne devices with laser interferometry over very large distances. Here I outline the concept study of a single resonant interferometer detector operating within a single drag-free satellite, capable of strain sensitivity better than 10^-20/√(Hz) for...
Xander Campman
(Shell Global Solutions International B.V.)
24/05/2016, 18:00
poster
We investigate to what extent subsurface information can be extracted from ambient seismic noise. Seismic noise is always present in seismic records and can be measured around the world, even in the quietest deserts. This makes noise an excellent candidate for seismic exploration or monitoring (and a nuisance for gravitational wave detection). The modal structure and strength of the noise...
Mr
Zeno Tornasi
(University of Glasgow)
24/05/2016, 18:00
poster
The dielectric mirror coatings in aLIGO are made of alternating layers of silica and tantala. Such materials exhibit high mechanical loss at low temperature, therefore reducing the advantages of cooling as the primary solution to coating thermal noise. Amorphous silicon is a promising candidate as a replacement of tantala as high refractive index material in a Bragg stack. Having a refractive...
Dr
Michal Was
(LAPP/CNRS)
24/05/2016, 18:00
poster
Most of the Advanced Virgo light sensing devices are located on 5 in
vacuum suspended benches. The benches are suspended from a triple
stage mSAS suspension, and the angular degrees of freedom are sensed
and controlled from the ground using LVDTs and coil-magnet
actuators. The angular control has stringent requirements 30 nrad rms
and 3e-15 rad/rtHz above 10 Hz. After introducing the...
Dr
Borja Sorazu
(University of Glasgow)
24/05/2016, 18:00
poster
At Glasgow we are working to improve the characterization of the aLIGO detector monolithic suspensions.
We have utilized realtime monitoring software to extract frequency, phase and amplitude of the fused silica suspension fibre violin modes. This has allowed the measurement of the Q-factors of some of these modes.
In addition, we have used preliminary FEA modeling of the fibre profiles,...
Mr
Naoki Aritomi
(University of Tokyo)
24/05/2016, 18:00
poster
For reduction of magnetic noise of coil-magnet actuators, we developed a new type of actuator; coil-coil actuator. It consists of only coils instead of magnet and current applied to the coils is modulated. We can choose any modulation frequency to reduce ambient magnetic noise coupling, while keeping the actuation force sufficiently strong. In this poster, we show our experimental results for...
Dr
Sabina Huttner
(University of Glasgow)
24/05/2016, 18:00
Speedmeters are becoming interesting for third generation gravitational wave detectors. Here we compare a new kind of sloshing-Sagnac interferometer with the ring-Sagnac interferometer. The sloshing-Sagnac requires only linear cavities and has alternating resonant and anti-resonant cavities, which act as a type of Khalili-cavities. These have the potential advantage of allowing a reduction of...
Mr
Raymond Robie
(University of Glasgow)
24/05/2016, 18:00
poster
Coating thermal noise is the limiting factor for detector strain sensitivity in the most sensitive frequency band. Future gravitational wave detectors are proposed to operate at cryogenic temperatures, where the mechanical loss of the low-index, amorphous silica coating layers is not well characterized and stands to be the dominant source of noise in the multi-layer mirror coating stack if...
Matteo Leonardi
(TIFP)
24/05/2016, 18:00
poster
Recent works (AEI-GEO600 and LIGO collaboration) demonstrated that the squeezing technology is one of the major and more urgent upgrades of the 2nd generation of GW detectors. They demonstrated also that to completely benefit from the injection of a squeezed state into the ITF (IFO), frequency dependent squeezing is a must. The LIGO collaboration already started to realize his own freq....
Mr
David Vine
(SUPA, University of the West of Scotland)
24/05/2016, 18:00
poster
Brownian thermal noise associated with the multilayer mirror coatings continues to limit the sensitivity of GW detectors within their most sensitive frequency band. Currently these coatings are fabricated using ion beam deposition (IBD), delivering sub-ppm-level optical absorption and ppm-level scatter. However, further reductions in mechanical dissipation will be essential to fully exploit...
Mr
Omar de Varona
(LaserZentrum Hannover)
24/05/2016, 18:00
poster
After the first direct detection of gravitational waves, the GW community faces the challenge of improving the frequency range and sensitivity of the next generation of GWDs. Two approaches to achieve it are the power scaling of laser sources and the use of cryogenically cooled crystalline silicon-based optical components, which requires the operation at longer wavelength. These improvements...
Stefanie Kroker
(Braunschweig University of Technology, Physikalisch-Technische Bundesanstalt)
24/05/2016, 18:00
poster
Coating thermal noise is known to be a crucial limitation of future gravitational wave detectors’ sensitivity. As a potential solution for this issue is given by replacing conventional multilayer based optical components by monolithic crystalline grating reflectors. In this contribution thermal noise in grating reflectors is directly related to the electromagnetic field distribution in these...
Dr
Ayaka Shoda
(NAOJ)
24/05/2016, 18:00
poster
KAGRA is an interferometric gravitational-wave (GW) detector with 3-km arms in Japan.
One of the main features of KAGRA is that it is constructed underground of the mountain.
The underground has been considered to be suitable for the GW detectors since the environmental noise, such as seismic noise, is smaller.
On the other hand, there are several problems characteristic in underground,...
Dr
Kirill Tokmakov
(University of Strathclyde, Glasgow, UK.)
24/05/2016, 18:00
poster
The diameter of the silica fibers used in the 40 kg quasi-monolithic aLIGO test mass suspensions was chosen as d = 400 µm to keep the bounce frequency below 10 Hz, and the violin mode frequencies above 500 Hz. For further improvement of detector performance at low-frequency reducing the vertical bounce mode frequency (linearly proportional to the fiber diameter) would be beneficial. A....
Mr
Daniel Toyra
(University of Birmingham)
24/05/2016, 18:00
poster
FINESSE is a free and open source frequency domain modelling software for optical experiments. FINESSE and its Python wrapper PyKat are used in commissioning and design of gravitational wave detectors. We have recently enabled for modelling of multimode squeezing and parametric instability. The parametric instability model has successfully been tested against first experimental results....
Matthieu Gosselin
(EGO, European Gravitational Observatory)
24/05/2016, 18:00
poster
We want to design a fibered electro-optic modulator and a fibered Faraday isolator able to withstand power greater than 100W. The aim of such components would be to simplify the path between the laser, possibly a fiber laser, and the under vacuum injection bench. By doing that we will reduce in particular the beam jitter noise.
The main difficulty is about the fiber itself: how to keep a...
Ms
Margot Phelps
(Institute for Gravitational Research, University of Glasgow)
24/05/2016, 18:00
poster
Pure indium bonds to itself and non-metallic substrates like fused silica with comparable ease. Its vacuum compatibility, thermal conductivity [1], malleability and low mechanical loss [2,3] and low melt point also make it a good candidate for use in cryogenic systems. Currently it is proposed for use in the sapphire KAGRA suspensions [6] as well as a possibility for the silicon interfaces of...
Mr
Shogo Kambara
(University of Toyama)
24/05/2016, 18:00
poster
[Background]
I installed Input Mode Cleaner(IMC) in iKAGRA and did mode-matching for IMC using two lens. IMC is a big triangle cavity.
Kyung Ha Lee
(University of Glasgow)
24/05/2016, 18:00
poster
To increase the sensitivity of the current interferometric gravitational wave detectors,
an upgrade plan for the US based detectors, or “Advanced LIGO (aLIGO),” is being
studied. As part of this upgrade, changing the mass, stress, and length of the suspension for
the mirrors in the interferometers is considered to improve noise sources. From the previous
year’s Matlab modeling result, the...
Valerio Boschi
(PI)
24/05/2016, 18:00
poster
We present a compact and light low frequency sensor based on a horizontal folded pendulum mechanical design. The device can be used as an inertial sensor for the control system of seismic attenuators of present and future gravitational wave detectors.
The instrument has been developed by the Applied Physics Group of the University of Salerno while the readout, control electronics and software...
Ms
Marina Trad Nery
(Albert Einstein Institute)
24/05/2016, 18:00
poster
The fundamental limit of all future generation of interferometric gravitational wave detectors, namely quantum radiation pressure noise and photon shot noise, can only be reached with an improved laser power stability. The traditional active power stabilization schemes have also a fundamental limit set by the quantum noise (shot noise) in the sensing process which is bound by technical...
Dr
Nicholas Lockerbie
(University of Strathclyde)
24/05/2016, 18:00
poster
The suspension systems for future Gravitational Wave (GW) detectors require an improved level of immunity to sources of mechanical perturbation of their suspended test-masses. The displacement sensors used to mitigate such perturbations (OSEMs) need to be upgraded for improving their performance in frequency range < 1 Hz. The conceptual design of displacement shadow sensors utilising a...
Dr
Yuta Michimura
(Department of Physics, University of Tokyo)
24/05/2016, 18:00
poster
An optomechanical device reaching the standard quantum limit (SQL) of a force measurement plays a prominent roll for studying quantum mechanics. To prepare such a device, a mechanical oscillator well isolated from the environment is essential for the reduction of thermal disturbances. Here we propose an optical levitation of a mirror with two vertical Fabry-Perot cavities linearly aligned. We...
Rene Glaser
(FSU Jena / IFK / TTP)
24/05/2016, 18:00
poster
The photoelastic coefficients p11-p12 and p44 of silicon for light of a wavelength of 1550 nm was measured using a rotating quarter wave plate polarimeter. The results p11-p12 = (-0.1139±0.0014) and p44 = (-0.0501±0.0014) for room temperature agree well with previously published data for various wavelengths. Additional measurements for the temperature dependence of the p11-p12 coefficients...
Mr
Yutaro Enomoto
(ICRR, University of Tokyo)
24/05/2016, 18:00
poster
The design sensitivity of bKAGRA is limited by quantum noise for almost all the observation frequency band. As the first detection of gravitational waves by Advanced LIGO shows, it would be especially important to improve the sensitivity around 100 Hz, where radiation pressure noise would be dominant. To reduce radiation pressure noise and beat the standard quantum limit, a method where the...
Mr
Koji Nagano
(ICRR)
24/05/2016, 18:00
poster
In KAGRA, a ponderomotive squeezing technique with a homodyne detection is going to be used for reducing radiation pressure noise. For demonstrating the reduction technique, at first, radiation pressure noise should be observed in wide frequency range. For that purpose, the high finesse Fabry-Perot cavity with a suspended tiny mirror is used for enhancing radiation pressure noise. However,...
Tomofumi Shimoda
(University of Tokyo)
24/05/2016, 18:00
poster
TOBA(TOrsion-Bar Antenna) is a gravitational wave detector using a torsion pendulum. The resonant frequency of torsional motion is ~1mHz, therefore it is sensitive to gravitational waves at lower frequency band (0.1-10Hz) even on the ground. Two prototype TOBAs were developed and they achieved strain sensitivity h ~ 1e-8/rtHz @0.1Hz - 1e-10/rtHz @5Hz. One of the dominant noise sources for them...
Federico Paoletti
(PI)
24/05/2016, 18:00
Mitigation works recently done in AdVirgo aiming to a reduction of low frequency magnetic noise pollution in experimental sensible areas.
Mr
Gregoire Lacaille
(Gooch and Housego)
24/05/2016, 18:00
poster
Silicate Bonding has been used to assemble fused silica suspensions with low mechanical loss in quasi-monolithic optical systems for space missions aimed at tests of GR and in ground-based GW detectors. The technique also has broader applications including the construction of compound optical systems capable of withstanding high laser powers. Study of the optical properties of components...
Mr
Masayuki Nakano
(ICRR)
24/05/2016, 18:00
poster
In this poster, the summary of the input optics for the iKAGRA(initial KAGRA) will be reported.
The iKAGRA operation was done in March and April in 2016. The input optics for iKAGRA includes the PSL(pre-stabilized laser), the IMC (input mode cleaner), IFI (input Faraday isolator) and IMMT(input mode matching telescope). In this poster mainly the PSL and the IMC will be reported.
Mrs
Mariela Masso Reid
(Institute for Gravitational Research/University of Glasgow)
24/05/2016, 18:00
poster
Future generations of gravitational wave detectors plan to use cryogenics in order to further reduce thermal noise associated with the mirror test masses and their suspensions. Characterising the thermal conductivity of the candidate materials for these mirror suspension systems (e.g. single-crystal silicon and sapphire), and quantifying the optimum heat flow through compatible bonding...
Marine Ducrot
(LAPP)
24/05/2016, 18:00
poster
The Advanced Virgo OMC is composed of two monolithic cavities placed in
series. The light is resonating in the fused silica substrate, which
yields a length noise bounded by thermo-refractive noise.
After introducing the specifications on the OMC length noise, tests and
results of length-noise measurements at the level of the thermo-refractive-noise will be presented.
We will also discuss...
Matteo Lorenzini
(GSSI)
24/05/2016, 18:00
poster
For mechanical resonators in the acoustic band, thermo-elastic noise can be the dominant contribution to the thermal noise spectrum. Silicon membranes show a prominent thermoelastic peak below few kHz; silicon is widely used in precision applications and it represents a suitable solution for the test masses of future cryogenic GW detectors. We measured with GeNS the thermoelastic loss in a...
Prof.
Masaki Ando
(University of Tokyo)
24/05/2016, 18:00
poster
We are developing a new-type of gravitational-wave antenna, named TOBA (TOrsion-Bar Antenna). I will present the current status of our reaesch activities.
Ms
Vaishali Adya
(Leibniz Universität Hannover / AEI)
24/05/2016, 18:00
poster
The Einstein Telescope (ET) is a third-generation gravitational wave observatory with a target sensitivity of more than an order of magnitude higher than the current advanced detectors. ET will be located underground,consisting of three nested detectors, each of which is composed of two interferometers in xylophone configuration. In this poster we revisit the technique of Twin Signal Recycling...
Mr
Jan-Simon Hennig
(University of Glasgow)
24/05/2016, 18:00
poster
The main goal of the Glasgow Sagnac Speed Meter is to show reduced back action noise compared to a Michelson interferometer with equivalent parameters. In order to ensure limitation by back action noise the input test masses of the two triangular arm cavities are chosen to be 1g mirrors. To achieve the necessary isolation from seismic motion all optics need to be suspended by multi-cascaded...
Mr
Koki Okutomi
(Sokendai (GUAS))
24/05/2016, 18:00
poster
KAGRA is a Japanese interferometric gravitational-wave telescope with an arm length of 3 km. Main features of KAGRA are 1) placing underground and 2) cooling down mirrors to cryogenic temperature. The test operation with room temperature is over in April 2016.
We achieve vibration isolation of mirrors with long multistage suspension systems called seismic attenuation systems (SAS.) Each...
