GWADW2016 - Impact of Recent Discoveries on Future Detector Design

22 May 2016, 17:00 → 28 May 2016, 18:00 Europe/Rome

Hotel Hermitage, La Biodola, Isola d'Elba

Francesco Fidecaro (PI), Syd Meshkov (Caltech)

The recent detection of the merger of  two high stellar mass black holes, thereby confirming the existence in nature of GW sources that have heretofore only been hypothesized, will surely influence the design of future GW detectors.   Massive binary systems have luminosities allowing the advanced detectors to see them to cosmological distance and provide most of their SNR in the mid-to-low frequency band of GW interferometers. However, we must ensure, in our design efforts, that frequencies both above and below this range are also adequately covered. With aLIGO having completed its first observational run and now in full commissioning mode to prepare for the second run later this year, with aVirgo expected to join this next run once they have performed preliminary commissioning, and with KAGRA in an advanced construction phase, we are entering the regime of observational astronomy using GWs. This is a propitious time to consider the impact of GW150914 on ideas for near term detector enhancements as well as on the design of future detectors. This workshop will explore a variety of technologies and concepts relevant to these goals.
At GWADW 2015, in Alaska, a new format was introduced which had two days of parallel sessions. The new format was deemed successful, and we will repeat it this year with slight variations.  There will be three parallel sessions instead of last year’s four, and these will be spread over three days, instead of two, thereby providing more time to interact.

 

Sunday, 22 May

17:00 Registration

19:30 Welcome Cocktail

Monday, 23 May

Plenary 1

1 Welcome

Speaker: Francesco Fidecaro (Pisa)

2 Setting the stage

Speaker: Francesco Fidecaro (Pisa)

Slides Fidecaro_20160523_GWADW2016.pdf

Plenary 1: GW150914: Effect on Near Term Plans

Conveners: Cole Miller (Maryland), Lisa Barsotti (LIGO-MIT)

3 What Binary Black Holes Teach

Speakers: Salvatore Vitale (LIGO MIT), Steven Fairhurst (Cardiff)

Slides G1601092_v4_final.pdf

4 High and Low Frequency Sensitivity Improvements

Speaker: Lisa Barsotti (LIGO-MIT)

10:30 coffee break

Plenary 2 - Science case for future Detectors

Convener: Bangalore Sathyaprakash (Cardiff University)

5 Global Network of 2G+ and 3G Detectors

Speaker: Bangalore Sathyaprakash (Cardiff University)

Slides 160523-GWADW-Elba.pdf

6 Multimessenger Astronomy

Speaker: Steven Fairhurst (Cardiff)

12:30 lunch

Plenary 3 - Workshop goals

Conveners: Dennis Coyne (LIGO Lab), Eric Gustafson (Caltech), Fabrice Matichard (MIT), Giampietro Cagnoli (LMA - UCBL), Iain Martin (University of Glasgow), Jan Harms (FI), Jo van den Brand (Nikhef - VU), Riccardo Bassiri (Stanford University)

7 A. Low frequency

Speakers: Jan Harms (FI), Jo van den Brand (Nikhef - VU)

Slides WorkshopGoals.pdf

8 B. Introduction to thermal noise workshop and goals

Speaker: GIANPIETRO CAGNOLI (LMA - UCBL)

Slides Introduction_ThNs_Cagnoli.pptx

9 C. Controls

Speakers: Dennis Coyne (LIGO Lab), Fabrice Matichard (MIT)

Slides GWADW_-_Controls_session_intro.pdf

17:30 coffee break

Plenary 4 - Cryogenics

Conveners: Kazuhiro Yamamoto (Institute for Cosmic Ray Research, The university of Tokyo), Kentaro Somiya (Caltech), Seiji Kawamura (ICRR - The University of Tokyo)

10 Cyogenics session overview

Speaker: Giles Hammond (University of Glasgow)

Slides G1601127_v2.pdf

11 Overview of the 20 K configuration

Speaker: KAZUHIRO YAMAMOTO (Institute for Cosmic Ray Research, The university of Tokyo)

Slides Yamamoto(23May2016).ppt

12 Overview of the 120 K configuration

Speaker: Christopher Wipf (Caltech LIGO)

Slides cryo.pdf

13 Cryogenics Round Table

Speakers: Christopher Wipf (Caltech LIGO), Giles Hammond (University of Glasgow), KAZUHIRO YAMAMOTO (Institute for Cosmic Ray Research, The university of Tokyo), Rana Adhikari (Caltech), Ronny Nawrodt (Friedrich-Schiller-University Jena)

Slides CryogenicSession.pdf

Tuesday, 24 May

Low frequency workshop

14 Newtonian Seismic Array at LHO

Speaker: Jenne Driggers (Caltech)

Slides LHOarrayUpdate.pdf

15 Ambient Seismic Noise

Speaker: Xander Campman (Shell)

Slides Campman_GWADW2016_(updated_21-5-2016)_--_long_version.pdf (Protected)

Thermal noise & coatings workshop

16 Amorphous dielectric coatings

Speaker: Martin Fejer (Stanford University)

Slides AmorphousDielectricCoatingsv4.pdf

17 Atomic structure investigations of amorphous coatings

Speaker: Riccardo Bassiri (Stanford University)

Slides Bassiri_GWADW2016_Structure_v1.pdf

18 Modeling coating thermal noise for gravitational wave detectors

Speaker: Chris Billman (University of Florida)

Slides BillmanModeling.pdf

19 New results on losses correlation with structure

Speaker: Elodie Coillet (Lyon)

Slides GWADW2016-CoilletE.pdf

10:35 coffee break

Low frequency workshop

20 Towards Low Frequency Gravitational Force Sensing

Speaker: Bram Slagmolen (The Australian National University)

Slides GWADW2016-Slagmolen-V1a.pdf

21 TOBA: a Low-frequency Gravitational-Wave AntennaMasaki

Speaker: Masaki Ando (Univ. of Tokyo)

Slides gwadw160524_ando.pdf

22 Sensitivity limits of atom interferometry gravity gradiometers and strainmeters

Speaker: Fiodor Sorrentino (INFN - Genova)

Slides Sorrentino_GWADW2016.pdf

Thermal noise & coatings workshop

23 Discussion

12:30 lunch

Plenary 5 - LISA Pathfinder

Convener: Stefano Vitale (MIT - LIGO)

24 LISA in the post detection and post LISA Pathfinder era

Speaker: Karsten Danzmann (AEI Hannover)

25 Toward LISA in the USA

Speaker: John Conklin (University of Florida)

Slides LISA_GWADW_Elba_20160524_R0.pdf

26 LISA Pathfinder scientific operations

Speaker: Stefano Vitale (TN)

17:30 cheese&wine

Poster Session

27 A high-isolation, low-loss, in-vacuum, thermally-controlled Faraday isolator

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 are presented.

Speaker: maddalena mantovani (EGO)

28 A study of contamination in gravitational wave detectors

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 try to find how much dust is put on mirrors and how much optical loss will be generated from various size of dust. For this purpose, we prepared high reflective mirrors contaminated by the NIST traceable standard particles that have uniform size and the optical loss was checked by the storage time and transfer function of Fabry-Perot cavity composed of these contaminated mirrors. The distribution density of the NIST particle on mirrors was checked by microscope and image analysis method. As the next step, we are going to measure the dependence of optical loss on the number and size of particles.

Speaker: Mr Kunihiko Hasegawa (Institute for Cosmic Ray Research, the University of Tokyo,)

29 A Tunable Resonant Detector for Low Frequency Gravitational Waves

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 gravitational waves in the frequency range 0.001 Hz to 0.1 Hz. The resonance frequency and bandwidth are optically tunable, enabling continuous tracking of slowly evolving massive BH binary sources emitting in this frequency range. The interferometer operates in the Fabry-Perot mode with weakly coupled mass-mirrors with low resonance frequency and high Q, and a near-resonant auxiliary laser tunes the frequency using optical spring effect. The F-P cavity and moderate Q enables resonant strain sensitivity about 10^-20/√(Hz) and tunability enables resonant tracking for long integration.

Speaker: Prof. CS Unnikrishnan (Tata Institute of Fundamental Research, Mumbai, India)

30 Ambient seismic noise and its potential use in seismic exploration and monitoring

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 field depend on several factors, such as noise-source distribution and mechanism, depth of observation, atmospheric conditions, geographical location of observation, local geology, regional tectonic activity, etc. We study the characteristics of seismic noise in the frequency range 0.05-10 Hz. We discuss the measurement and analysis of seismic noise and present results from experiments in The Netherlands, Libya, Egypt and Saudi Arabia. Next, we review methods to extract subsurface information from noise. Finally we show examples of successful surface-wave or body-wave retrieval from seismic noise.

Speaker: Xander Campman (Shell Global Solutions International B.V.)

31 Amorphous silicon as low loss, high refractive index material for dielectric mirror coatings

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 index higher than tantala, it allows for thinner layers, its low loss enables low thermal noise coatings. High optical absorption is the main limitation in exploiting aSi. We report on the characterisation of optical absorption and microscopic structure of amorphous silicon films.

Speaker: Mr Zeno Tornasi (University of Glasgow)

Poster Tornasi-UofGlasgow_Elba16_AmorphousSilicon.pdf

32 Angular control of Advanced Virgo suspended benches

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 system design, we present the first in air results of controlling the fully integrated system and striving to achieve these requirements.

Speaker: Dr Michal Was (LAPP/CNRS)

33 Characterisation of the aLIGO monolithic suspensions

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, measured during aLIGO detector suspension installation, to predict the observed departure of the frequencies of violin mode harmonics from whole multiples of the fundamental frequency. Using these analysis techniques for the lower glass stage of the suspension, in the future we shall compare the measured violin mode Q values with detailed FEA modeling of the aLIGO detectors monolithic suspensions. This information will help to better understand the aLIGO detectors low frequency noise performance.

Speaker: Dr Borja Sorazu (University of Glasgow)

Slides Characterisation_of_the_aLIGO_monolithic_suspensions_-_Borja_Sorazu_2016_-_FINAL.pdf

34 Coil-Coil Actuator for reduction of magnetic noise

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 evaluation and reduction of the magnetic noise of a coil-coil actuator.

Speaker: Mr Naoki Aritomi (University of Tokyo)

35 Comparison of ring-Sagnac and sloshing-Sagnac interferometer

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 the coating thermal noise. Here we evaluate the quantum noise limited sensitivity and the coating noise reduction compared to a conventional position-meter (such as Advanced LIGO).

Speaker: Dr Sabina Huttner (University of Glasgow)

36 Cryogenic mechanical loss of IBS silica

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 amorphous silicon is found to be a viable replacement for the high-index layers (currently 25% Ti:Ta2O5). The low temperature mechanical loss of ion-beam sputtered silica is presented for a number of post-deposition heat treatments.

Speaker: Mr Raymond Robie (University of Glasgow)

37 Developing a squeezed light source at Virgo site

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. dependent squeezer, to be implemented into the ITFs. In this framework, I’ll present the steps undertaken from various INFN groups to realize a first prototype of freq. independent squeezer with the specific aim to be implemented in Advanced Virgo.

Speaker: Matteo Leonardi (TIFP)

38 Development of ultra-low optical and mechanical loss aSi coatings using novel ECR ion beam deposition

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 planned upgrades to Advanced LIGO, e.g. squeezing. Researchers at UWS and UoG have developed a new generation of IBD. The ion source uses electron cyclotron resonance (ECR) within a λ/4 microwave (2.4GHz) cavity to produce an ultra-clean (filament-free) plasma and incorporates a gridless extraction supplying ion energies up to 15keV. Initial results of aSi films show optical absorption of 20ppm at 1550nm for a λ/4 stack (tenfold reduction) with an upper limit on the mechanical loss of 1.2e-4 (factor of 2 reduction over Ta2O5). Details of heated substrate deposition (up to 500C) are also presented.

Speaker: Mr David Vine (SUPA, University of the West of Scotland)

Slides 2016-05_GWADW_Elba.pptx

39 Dynamics of Fiber Amplifiers in the Context of Gravitational Wave Detectors’ Laser Sources

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 need new concepts of laser sources that are not totally defined yet. Fiber amplifiers in Master Oscillator Power Amplifier (MOPA) configuration are demonstrating to be good candidates to meet the requirements of the next generation of GWDs. In this work we study the non-linear processes of gain and temporal dynamics in Er-doped, Yb-doped and Er:Yb-codoped fiber amplifiers with the aim of developing single-frequency, high-power fiber sources at 1μm and 1.5μm with long-term stability. The study of the amplifier dynamics also provides valuable information to realize stabilization loops.

Speaker: Mr Omar de Varona (LaserZentrum Hannover)

40 Electromagnetic Derivation of Thermal Noise in Grating Reflectors

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 structures. The presented results enable the physical understanding of noise processes in grating reflectors and provide the possibility for a targeted optimization of the structure parameters for minimized thermal noise in the future.

Speaker: Stefanie Kroker (Braunschweig University of Technology, Physikalisch-Technische Bundesanstalt)

41 Environment at the underground GW detector KAGRA

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, such as spring water. In this poster, we will explain the current situation inside the KAGRA tunnel, using the environmental data took at the KAGRA site, such as seismic level, humidity, temperature, and so on.

Speaker: Dr Ayaka Shoda (NAOJ)

42 Factors pertaining to the strength of four-fiber monolithic silica test mass suspensions.

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. Heptonstall et al suggested that the fiber diameter can be reduced to 288 µm; this thickness is sufficient to give a fiber strength three times larger than the static load in aLIGO suspension (still providing a reasonable safety margin). We analyze the strength of welded 4-fiber suspension. The additional factors such as strength of welded joints or stock misalignments may limit the suspension strength. The fiber's thickness is one of the few competitive limiting factors. In such case the fiber's diameter can be made near 300 µm and the full suspension strength should not be significantly affected.

Speaker: Dr Kirill Tokmakov (University of Strathclyde, Glasgow, UK.)

Poster Poster-5.pdf

43 FINESSE 2.1 - with Multimode Squeezing

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. Further we announce a web page for learning gravitational wave laser interferometry, FINESSE and PyKat. The material is available in HTML and IPython/Jupyter Notebook formats, and is thought to serve as both self-study material for beginners as well as reference material for experienced users.

Speaker: Mr Daniel Toyra (University of Birmingham)

44 High power fibered electro-optics components

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 good beam quality (TEM00, polarization, noises...) while avoiding all the non linear effects that appear in fibers for such densities of power? Here we present an active method to keep a stable injection and avoid the noises coming from a misalignment between the input beam and the fiber. The error signal that we use is generated by a scan of the input of the fiber. We also present the investigations on a Large Mode Area fiber. Especially the compromise that has to be found between the quality of the output beam and the power that can be reach before facing Stimulated Brillouin Scattering.

Speaker: Matthieu Gosselin (EGO, European Gravitational Observatory)

45 Indium bond research for crystalline cryogenic suspensions

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 the future ET detector [5]. This poster explains two approaches to achieve strong, low noise indium bonds. One using layers of indium nanometres thick evaporated onto silicon substrates and bonded at the Institute for Gravitational Research in Glasgow. A second approach uses inductive heating of indium foil between sapphire substrates with the aim of bonding suspensions in a detector in-situ, conducted in part at the ICRR in Tokyo, Japan.

Speaker: Ms Margot Phelps (Institute for Gravitational Research, University of Glasgow)

46 Installation of Input Mode Cleaner of iKAGRA

[Background] I installed Input Mode Cleaner(IMC) in iKAGRA and did mode-matching for IMC using two lens. IMC is a big triangle cavity.

Speaker: Mr Shogo Kambara (University of Toyama)

47 Investigation of Suspension Upgrades for the Advanced LIGO Gravitational Wave Detector

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 higher stress in the fibre and the longer last stage showed improvements in the detector’s sensitivity. Since the last stage of the suspension is held by fused silica fibres, which have very low loss to minimise suspension thermal noise, one of the challenges for this upgrade will be producing thinner and longer fibres that can hold the test mass safely. In this report, the impact laser stabilisation on fused silica fibres’ geometry and strength is being investigated to allow further improvements on fibre production to achieve aLIGO upgrades.

Speaker: Kyung Ha Lee (University of Glasgow)

48 Large band low frequency sensors based on Watt’s linkage for future generations of interferometric detectors

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 by the INFN Pisa Group.

Speaker: Valerio Boschi (PI)

Poster Poster_ET_2016_Barone_v2.pdf

49 Laser power stabilization for future gravitational wave detectors

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 limitations of the maximal detectable power. In this poster we study a new scheme for power stabilization in which power fluctuations are transferred to another observable, the phase of the light field. The great advantage of such a scheme is to use the full beam power in the transfer process, and hence not be limited by the relative shot noise in the sensing process used by the traditional schemes. We present different experimental setups and also their sensitivity to detect relative power fluctuations of 10-9/sqrt(Hz).

Speaker: Ms Marina Trad Nery (Albert Einstein Institute)

50 New OSEM results using a displacement-doubling prism-based flag

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 ‘displacement doubling prism’ [1] is presented. Reference: 1. N.A. Lockerbie, Nucl. Instrum. Meth. A, 741 (2014) 192–195.

Speaker: Dr Nicholas Lockerbie (University of Strathclyde)

Poster Strath_poster_Elba-2016_n.pdf

51 Optical levitation of a mirror

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 show the stability of the system and demonstrate the feasibility of reaching the SQL with this system.

Speaker: Dr Yuta Michimura (Department of Physics, University of Tokyo)

52 Photoelasticity of Silicon and its temperature dependence

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 were done using a similar setup combined with a cryostat allowing sample temperatures down to about 10 K. The measurements show a temperature dependence with a maximum deviation of about 10% relative to the room temperature value.

Speaker: Rene Glaser (FSU Jena / IFK / TTP)

53 Reduction of quantum noise for gravitational wave detector KAGRA (I)

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 ponderomotively-squeezed output field from the interferometer is detected with homodyne detection was proposed. For the demonstration of the technique to reduce radiation pressure noise, an experiment with a cavity which has a milligram-scale suspended mirror as a end test mass is ongoing in our laboratory. In this presentation, overview and current status of the experiment are presented. Especially, a new method of intensity stabilization of light for the reduction of classical radiation pressure noise below quantum radiation pressure noise is presented.

Speaker: Mr Yutaro Enomoto (ICRR, University of Tokyo)

54 Reduction of quantum noise for gravitational wave detector KAGRA (II)

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, when the intracivity power increases, an angular instability generated by radiation pressure can occur in the cavity depending on the geometry of the cavity. For circumventing the angular instability of the cavity, an angular control system using radiation pressure itself was invented. It was confirmed experimentally that the cavity consisting a suspended 23-mg mirror was unstable without the angular control system under high intracavity power condition. Moreover, with the same intracavity power condition, it was also proved that, using the angular control system, the cavity could be operated stably.

Speaker: Mr Koji Nagano (ICRR)

55 Reduction of Seismic Coupling Noise for TOBA

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 was seismic noise, especially coupling noise from translational seismic motion to test mass rotation. In order to improve the sensitivity and detect gravitational waves, it is indispensable to reduce this coupling noise. Here we show the specified five coupling routes and reduction methods for them.

Speaker: Tomofumi Shimoda (University of Tokyo)

56 Reduction of Virgo Low Frequency environmental magnetic noise

Mitigation works recently done in AdVirgo aiming to a reduction of low frequency magnetic noise pollution in experimental sensible areas.

Speaker: Federico Paoletti (PI)

57 Silicate bonding extends to the photonics industry

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 assembled using this technique is thus of interest. We report on the bonding of phosphate glass and the measurement of some of the properties of the bond: optical index,thickness, reflectance and Light Induced Damage Threshold (LIDT). The measured reflectance at 532nm is below 0.3% while the LIDT at 1535nm is 650MW/cm^2 (6.5J/cm^2 ). Both these values are in line with the usual requirements for high power lasers which opens the way to promising applications. Future work should focus on extending the measurements and bonding other materials for applications in photonics such as YAG or sapphire.

Speaker: Mr Gregoire Lacaille (Gooch and Housego)

58 The input optics for iKAGRA

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.

Speaker: Mr Masayuki Nakano (ICRR)

59 Thermal conductivity of bonded materials for future generation gravitational wave observatories

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 techniques for these materials, is therefore crucial. Preliminary results are presented here for hydroxide catalysis bonded silicon (100) samples of combined dimension 5x5x40mm. These results show a lower limit for the thermal conductivity of the bond at the level of 0.059 W/m/K. Studies will continue in order to better evaluate the thermal conductivity of hydroxide catalysis bonds, and investigate methods by which it may be optimised.

Speaker: Mrs Mariela Masso Reid (Institute for Gravitational Research/University of Glasgow)

60 Thermo-refractive noise measurement in the Advanced Virgo Output Mode Cleaner

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 the impact of the thermo-refractive noise on future detectors.

Speaker: Marine Ducrot (LAPP)

Poster Ducrot_Was_GWADW_poster.pdf

61 Thermoelastic damping in silicon and metallic discs: the mode-dependent branching effect

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 set of silicon disk samples, and found a dependancy of the loss angle upon the normal mode geometry. This behavior is deduced from the general theory in free disks but, to our knowledge, it was not yet shown in experiments. We also demonstrated that this feature is seen in homogeneous CuBe disks, proving that it is not related to the silicon anisotropy. We present the results of our measurements and a new theoretical approach exploiting the entropy increase; eventually, the mode-dependent loss is explained in terms of the ratio among dilatation energy and total elastic energy.

Speaker: Matteo Lorenzini (GSSI)

62 TOBA: a Low-frequency Gravitational-Wave Antenna

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.

Speaker: Prof. Masaki Ando (University of Tokyo)

63 Trade-offs for squeezed light injection in a non-perfect world

(will follow)

Speaker: Emil Schreiber (Albert Einstein Institute Hannover)

64 Twin Signal Recycling for the Einstein Telescope

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 (TSR), which leads to simultaneous resonant enhancement of both the upper and the lower signal sidebands. A comparison of this technique for a futuristic GEO-HF with arm cavities and ET-LF is also discussed here. For the latter, a preliminary attempt at a broadband reduction in quantum noise limited sensitivity by use of frequency dependent squeezing has been simulated using the numerical interferometer simulation package Finesse. The benefits of both these techniques are weighed by measuring the quantum noise limited sensitivity of ET-LF detuned signal recycling with twin signal recycled ET-LF.

Speaker: Ms Vaishali Adya (Leibniz Universität Hannover / AEI)

65 Ultra-quiet Mirror Suspensions for the Glasgow Sagnac Speed Meter

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 pendulums. This poster presents the different suspension designs used in this proof of concept experiment and highlights the challenges for the 1g mirror suspensions.

Speaker: Mr Jan-Simon Hennig (University of Glasgow)

66 Vibration Isolation System for KAGRA: Overview and Results in the First Operation

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 stage has functions to lower its resonant frequency. Because the whole of suspension system has to be operated with the interferometer, its control system becomes very complicated. I report an overview of KAGRA's vibration isolation systems and results of suspension performance in the first operation.

Speaker: Mr Koki Okutomi (Sokendai (GUAS))

Wednesday, 25 May

Controls Workshop: Angular control

Convener: Jenne Driggers (Caltech)

67 Angular loop consideration

Speaker: Jenne Driggers (Caltech)

Slides AngularLoopConsiderations.pdf

68 Angular control of Advanced Virgo suspended benches

Speaker: Michal Was (LAPP/CNRS)

Slides Was_GWADW2016-05_localControl.pdf

69 Hopes and Dreams: One Transfer Func4on Fi6ng Program to Rule Them All

Speaker: Jeffrey Kissel (CalTech)

Slides kissel_G1601173-v1.pdf

70 Radiation pressure induced instability

71 Discussion

Thermal noise & coatings workshop

72 Amorphous optical coatings for gravitational-wave interferometers

Speaker: Massimo Granata (Laboratoire des Matériaux Avancés - CNRS)

Slides GWADW16_Granata_LMAcoatings.pdf

73 Development of ultra-low optical and mechanical loss aSi coatings using novel ECR ion beam deposition

Speaker: Stuart Reid (University of the West of Scotland)

Slides StuartReid_IainMartin_2016-05_GWADW_Elba.compressed.pdf

74 Optical absorption of amorphous silicon coatings(included in previous slides)

Speaker: Iain Martin (University of Glasgow)

75 Thermoelastic damping in silicon and metallic discs: the mode shape dependent branching effect

Speaker: Matteo Lorenzini (GSSI)

Slides GWADW16_Lorenzini.pptx

10:30 coffee break

Controls Workshop: Local and Global Control

Convener: Jeffrey Kissel (CalTech)

76 MIMO damping

77 Fitting tools

78 How to use the earthquakes arrival predictor to put the IFO in robust mode

Speaker: Sebastien Biscans (MIT LIGO)

79 Present and future of superattenuator control system

Speaker: Valerio Boschi (PI)

Slides ELBA_-_2016.pdf

80 Feedforward control for arm cavities

81 Discussion

Thermal noise & coatings workshop

82 Coatings Thermal noise workshop discussion points

Speaker: Riccardo Bassiri (Stanford University)

Slides Coating_Thermal_Noise_Workshop_discussion_points_Wed.pdf

83 Discussion

12:30 lunch

Plenary 6 - Enhanced interferometers near term (<12 years)

Conveners: Daniel Sigg (LIGO Hanford Observatory), Matteo Barsuglia (APC-CNRS), Rana Adhikari (Caltech)

84 Summary of science goals

Speaker: Yanbei Chen (California Institute of Technology)

Slides VoyagerScienceCaseYanbeiChen.pdf

85 LIGO: the A+ upgrade

Speaker: Lisa Barsotti (LIGO-MIT)

Slides G1601199-v2.pdf

86 Virgo upgrade plans

Speaker: Gianpietro Cagnoli (LMA - UCBL)

Slides Enhanced_Virgo_Cagnoli_GWADW2016.pdf

87 Squeezing with long filter cavities

Speaker: Eleonora Capocasa (APC)

Slides long_filter_cavitiesV8.pdf

88 Balanced homodyne readout

Speaker: Sebastian Steinlechner (University of Glasgow)

Slides gwadw2016_bhd.pdf

89 Discussion

17:30 coffee break

Plenary 6 - Enhanced interferometers near term (<12 years)

Conveners: Daniel Sigg (LIGO Hanford Observatory), Matteo Barsuglia (APC-CNRS), Rana Adhikari (Caltech)

90 Coating - What's available now and in the 5-10 years

Speaker: Riccardo Bassiri (Stanford University)

Slides CoatingsNow(1).pdf

91 What if we are stuck with the coatings I

Speaker: Stefan Ballmer (Syracuse University)

Slides GWADW2016_G1601177_stuckCoatingscomp.pptx

92 What if we are stuck with the coatings II

Slides freise_GWADW_wide_beams_2016.pdf

93 Discussion

94 Voyager: Pros and cons of the cryo-silicon-2micron idea

Speaker: Rana Adhikari (Caltech)

Slides VoyagerStat-2016.pdf

95 Discussion

20:00 Workshop reception

Thursday, 26 May

Controls Workshop: Learning Algorithms for Tuning Global IFO Control Parameters

Convener: Rana Adhikari (Caltech)

96 What environmental changes or instrument drifts require re-tuning

97 Define inputs and outputs

98 Learning Methods for Interferometers

Speaker: Rana Adhikari (Caltech)

Slides Machines.pdf

99 Discussion

Low frequency workshop

100 Low-frequency seismic sensors

Speaker: Conor Mow-Lowry (University of Birmingham)

Slides Conor_Elba_low_f_sensors.pdf

101 Sensor development and characterization at Nikhef

Speaker: Maria Bader (Nikhef)

102 MEMS sensor development

Speaker: Boris Boom (Nikhef)

10:30 coffee break

Controls Workshop: Controls Considerations for Next Generation Detectors Designs

Convener: Dennis Coyne (LIGO Lab)

103 Brief description of next gen concepts

Slides G1601213-v1_Controls_Considerations_for_Next_Generation_GW_Detectors.pdf

104 Some thoughts on controls challenges, considerations for discussion

Slides G1601212-v1__thoughts_on_ML_for_GW_detectors.pdf Machines.pdf

105 Discussion

Low frequency workshop

106 Seismic rotational measurements

Speaker: Angela Di Virgilio (PI)

Slides AngelaGWADW.pdf

107 NN modeling for MIGA

Speaker: Sophie Pelisson (LP2N-IOA)

Slides Talk_Pelisson_GWADW16.pdf

108 Atmospheric NN modeling

Speaker: Donatella Fiorucci (CNRS)

Slides Presentation_ELBA_5_DF.pdf

12:30 lunch

Coordination of Future Development of Large Detectors

Conveners: David Reitze (Caktech), Michele Punturo (PG), Ms Sheila Rowan (University of Glasgow)

109 Possible models for GWIC’s role

Speaker: Sheila Rowan (University of Glasgow)

110 Need for coordinated R&D: the ET perspective

Speaker: Michele Punturo (PG)

Slides ET_-_Need_for_coordinated_R&D.pdf

111 Need for coordinated R&D: the LIGO perspective

Speaker: David Reitze (Caltech)

Slides Reitze_GWADW_2016_talk.pdf

Plenary 7 - Future detectors requirements, goals, possibilities

Conveners: Harald Lueck (AEI Hannover (MPI f. gravitational Physics / Inst. f. Grav.physics Leibniz Uni Hannover)), Matthew Evans (MIT), Michele Punturo (PG)

slides GWDAW_NF_ScienceCase.pdf

112 Science targets for future detectors

Speaker: Salvatore Vitale (LIGO MIT)

Slides MultiBandElba.pdf

113 Synergy between space and terrestrial detectors

Speaker: Alberto Sesana (Birmingham)

114 Low Frequency Noise Impact - Summary

Speakers: Jan Harms (FI), Jenne Driggers (Caltech)

Slides LowFreqImpact.pdf

115 Lenses and wedges – Do these make sense for long arms?

Speaker: Stefan Ballmer (Syracuse University)

Slides GWADW2016_G1601202_TFI_SB.pdf

17:30 coffee break

Plenary 7 - Future detectors requirements, goals, possibilities

Conveners: Harald Lueck (AEI Hannover (MPI f. gravitational Physics / Inst. f. Grav.physics Leibniz Uni Hannover)), Matthew Evans (MIT), Michele Punturo (PG)

slides GWDAW_NF_ScienceCase.pdf

116 Scattering, technical noise and alignment, stability

Speaker: Matthew Evans (MIT)

117 Triangles vs Ls

Speaker: Andreas Freise (University of Birmingham)

Slides freise_GWADW_triangle_2016.pdf

118 Suspending 400kg mirrors

Speakers: Giles Hammond (University of Glasgow), Norna Robertson (LIGO-Caltech)

119 Heterogeneous detector networks discussion

Speaker: Daniel Sigg (LIGO Hanford Observatory)

Slides G1601117-v1.pdf

Friday, 27 May

Plenary 8 - IFO configurations & squeezing

Conveners: David McClelland (The Australian National University), Jean Pierre Zendri (PD), Roman Schnabel (Hamburg University)

120 Introduction

Speaker: David McClelland (The Australian National University)

Slides Plenary_8_Introduction_McClelland.pdf

121 Squeezing at 1064nm

Speaker: Henning Vahlbruch (AEI Hannover)

Slides 01c_GWADW2016.pdf

122 Squeezing at 1550nm and across the wavelengths

Speaker: Axel Schoenbeck (Hamburg University)

Slides Talk_Elba_Final_schoenbeck.pdf

123 Intracavity Squeezing I

Speaker: Yanbei Chen (California Institute of Technology)

Slides ArmFilteringYanbeiChen.pdf

124 Intracavity Squeezing II

Speaker: Kentaro Somiya (Caltech)

Slides Somiya160527.pdf

10:30 coffee break

Plenary 8 - IFO configurations & squeezing

Conveners: David McClelland (The Australian National University), Jean Pierre Zendri (PD), Roman Schnabel (Hamburg University)

125 Quantum dense metrology

Speaker: Sebastian Steinlechner (University of Glasgow)

Slides steinlechner_qdm.pdf

126 New Topology Speedmeter

Speaker: Shtefan Danilishin (University of Glasgow)

Slides Danilishin_GWADW2016_talk.pdf

127 Atom Interferometer GW Detectors

Speaker: Philippe Bouyer (Bordeaux)

12:30 lunch

Thermal noise & coatings workshop

Conveners: Eric Gustafson (Caltech), Gianpietro Cagnoli (LMA - UCBL), Iain Martin (University of Glasgow), Riccardo Bassiri (Stanford University)

128 Minimizing test mass thermal noise with crystalline coatings

Speaker: Garrett Cole (University of Vienna)

Slides GDC_GWADW_May_2016.pdf

129 Discussion

Plenary 9 - Workshop summaries

130 Low Frequency

Speakers: Jan Harms (FI), Jo van den Brand (Nikhef - VU)

131 Controls

Speakers: Dennis Coyne (LIGO Lab), Fabrice Matichard (MIT)

Slides GWADW_-_Controls_session_summary.pdf

17:30 coffee break

Plenary 9 - Workshop summaries

132 Thermal noise & Coatings

Speakers: Eric Gustafson (Caltech), Gianpietro Cagnoli (LMA - UCBL), Iain Martin (University of Glasgow), Riccardo Bassiri (Stanford University)

Slides GWADW2016_TNWoskshopSummary.pdf

Plenary 10 - Future plans

Conveners: Francesco Fidecaro (Pisa), Syd Meshkov (Caltech)

Summary

133 GWADW 2016 Summary

Speaker: Alberto Lazzarini (Caltech - LIGO)

Slides LAZZARINI-Summary-GWADW2016-v4.pdf