Measurement of the intrinsic mechanical loss of low-loss samples using a nodal support

Numata, Kenji; Bianc, Giuseppe Bertolotto; Ohishi, N.; Sekiya, Atsushi; Otsuka, Shigemi; Kawabe, K.; Ando, Masaki; Tsubono, K.

doi:10.1016/s0375-9601(00)00646-0

Cited by 31 publications

(14 citation statements)

References 11 publications

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“…In this paper we will assume that the loss angles associated with energy stored in strains parallel to the plane of the coating are all equal. This assumption is motivated by the observation that many isotropic, amorphous materials, like fused silica, do not show significantly different quality factors for many modes even though the relative magnitude of the various terms in the elastic energy varies significantly between the modes [18]. The measurements made at Glasgow and Stanford Universities further strengthen this assumption [15] -those measurements show no significant variation of the coating loss as the relative size of the different coating energy terms changes from mode to mode.…”

Section: Theorymentioning

confidence: 99%

Thermal noise in interferometric gravitational wave detectors due to dielectric optical coatings

Harry

Gretarsson

Saulson

et al. 2002

Class. Quantum Grav.

298

345

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We report on thermal noise from the internal friction of dielectric coatings made from alternating layers of Ta2O5 and SiO2 deposited on fused silica substrates. We present calculations of the thermal noise in gravitational wave interferometers due to optical coatings, when the material properties of the coating are different from those of the substrate and the mechanical loss angle in the coating is anisotropic. The loss angle in the coatings for strains parallel to the substrate surface was determined from ringdown experiments. We measured the mechanical quality factor of three fused silica samples with coatings deposited on them. The loss angle, φ (f ), of the coating material for strains parallel to the coated surface was found to be 4.2 ± 0.3 × 10 −4 for coatings deposited on commercially polished slides and 1.0 ± 0.3 × 10 −4 for a coating deposited on a superpolished disk. Using these numbers, we estimate the effect of coatings on thermal noise in the initial LIGO and advanced LIGO interferometers. We also find that the corresponding prediction for thermal noise in the 40 m LIGO prototype at Caltech is consistent with the noise data. These results are complemented by results for a different type of coating, presented in a companion paper.

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Section: Theorymentioning

confidence: 99%

Thermal noise in interferometric gravitational wave detectors due to dielectric optical coatings

Harry

Gretarsson

Saulson

et al. 2002

Class. Quantum Grav.

298

345

View full text Add to dashboard Cite

show abstract

“…Among the low CTE materials that are commonly used in ultra-stable cavities, ULE has a Q factor of 6.1 × 10 4 that is more than one order of magnitude larger than that of Zerodur (3.1 × 10 3 ). Furthermore, FS has an even larger Q factor of about 10 6 [35]. In cases where thermal noise limits are the ultimate limiting factor of achievable cavity stability, it is very effective to use a higher Q factor material (like FS) as mirror substrate while keeping ULE as spacer material.…”

Section: Calculation Of Thermal Noise Limitsmentioning

confidence: 99%

Design of an optical reference cavity with low thermal noise limit and flexible thermal expansion properties

et al. 2013

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An ultrastable optical reference cavity with re-entrant fused silica mirrors and a ULE spacer structure is designed through finite element analysis. The designed cavity has a low thermal noise limit of 1 × 10 −16 and a flexible zero crossing temperature of the effective coefficient of thermal expansion (CTE). The CTE zero crossing temperature difference between a composite cavity and a pure ULE cavity can be tuned from −10 • C to 23• C, which enables operation of the designed reference cavity near room temperature without worrying about the CTE zero crossing temperature of the ULE spacer. The design can be applied to cavities with different lengths. Vibration immunity of the cavity is also achieved through structure optimization. Lett. 82, 3799-3802 (1999

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“…6). Properties of sapphire as a cryogenic substrate material have been studied by several groups [87,[109][110][111] suggesting that sapphire has a very low mechanical loss. At cryogenic temperatures it reaches 2 × 10 −10 [87].…”

Section: Sapphirementioning

confidence: 99%

Challenges in thermal noise for 3rd generation of gravitational wave detectors

et al. 2010

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Various noise sources limit the sensitivity of current interferometric gravitational wave detectors, including seismic noise, thermal noise of the optical components and suspension elements and photon shot noise. Plans are in place for a suite of hardware upgrades which should increase the sensitivity of these detectors by reducing the various noise sources. With these designs for 2nd generation detectors mature, techniques for further improvement of detector sensitivity by a factor of approximately 10 are under study. A particular challenge is the reduction of the thermal noise associated with the interferometer mirrors and their suspensions. We review the current status of research on thermal noise in interferometric gravitational wave detectors. Aspects of possible techniques for use in future '3rd generation detectors' such as cryogenics and diffractive optics are discussed

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Measurement of the intrinsic mechanical loss of low-loss samples using a nodal support

Cited by 31 publications

References 11 publications

Thermal noise in interferometric gravitational wave detectors due to dielectric optical coatings

Thermal noise in interferometric gravitational wave detectors due to dielectric optical coatings

Design of an optical reference cavity with low thermal noise limit and flexible thermal expansion properties

Challenges in thermal noise for 3rd generation of gravitational wave detectors

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