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

Harry, G. M.; Gretarsson, A. M.; Saulson, P. R.; Kittelberger, S.; Penn, S.; Startin, William J.; Rowan, S.; Fejer, M. M.; Crooks, D. R. M.; Cagnoli, G.; Hough, J.; Nakagawa, N.

doi:10.1088/0264-9381/19/5/305

Cited by 298 publications

(361 citation statements)

References 26 publications

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“…1(b). The use of such a monocrystalline material structure allows for a significant reduction of the mechanical damping of the resonator when compared with dielectric reflectors [41] and simultaneously provides high optical reflectivity. The crystalline material used here is nominally identical in composition and individual layer thickness to the structures in Ref.…”

Section: Mechanical Motional State Reconstruction and State Preparatimentioning

confidence: 99%

Cooling-by-measurement and mechanical state tomography via pulsed optomechanics

et al. 2013

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Observing a physical quantity without disturbing it is a key capability for the control of individual quantum systems. Such back-action-evading or quantum-non-demolition measurements were first introduced in the 1970s in the context of gravitational wave detection to measure weak forces on test masses by high precision monitoring of their motion. Now, such techniques have become an indispensable tool in quantum science for preparing, manipulating, and detecting quantum states of light, atoms, and other quantum systems. Here we experimentally perform rapid optical quantumnoise-limited measurements of the position of a mechanical oscillator by using pulses of light with a duration much shorter than a period of mechanical motion. Using this back-action evading interaction we performed both state preparation and full state tomography of the mechanical motional state. We have reconstructed mechanical states with a position uncertainty reduced to 19 pm, limited by the quantum fluctuations of the optical pulse, and we have performed 'cooling-by-measurement' to reduce the mechanical mode temperature from an initial 1100 K to 16 K. Future improvements to this technique may allow for quantum squeezing of mechanical motion, even from room temperature, and reconstruction of non-classical states exhibiting negative regions in their phase-space quasi-probability distribution.Experiments are now beginning to investigate nonclassical motion of massive mechanical devices [1][2][3]. This opens up new perspectives for quantum-physics enhanced applications and for tests of the foundations of physics. A versatile approach to manipulate mechanical states of motion is provided by the interaction with electromagnetic radiation, typically confined to microwave or optical cavities. Such cavity-optomechanics experiments [4][5][6][7][8] have thus far largely concentrated on high sensitivity continuous monitoring of the mechanical position [9][10][11][12][13][14]. Because of the back-action imparted by the probe onto the measured object, the precision of such a measurement is fundamentally constrained by the standard quantum limit (SQL) [15,16], and therefore only allows for classical phase-space reconstruction [9,17,18]. In order to observe quantum mechanical features that are smaller than the mechanical zero-point motion, backaction-evading measurement techniques that can surpass the SQL [19,20] are required. Following the early insights of Braginsky, beating the standard quantum limit 'can be achieved only in one way: design the probe so it "sees" only the measured observable ' [15]. Such backaction evading techniques were first realized for the detection of optical quadratures [21][22][23] and have since been used for, e.g. precision measurement of atomic ensemble spin [24][25][26][27][28] and quantum non-demolition microwave photon counting [29]. In optomechanics, to perform a back-action evading measurement of the mechanical position, a time-dependent measurement scheme is required. One prominent example is the so-called 'two-tone app...

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Section: Mechanical Motional State Reconstruction and State Preparatimentioning

confidence: 99%

Cooling-by-measurement and mechanical state tomography via pulsed optomechanics

et al. 2013

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“…While the mirror substrate material chosen (like synthetic fused silica Heraeus Suprasil ® 3001 (http://optics. heraeus-quarzglas.com/en/productsapplications/productdetail_1938.aspx) or 3002) shows low mechanical dissipation, the high refraction component in the dielectric coating (Tantalum-pentoxide Ta 2 O 5 ) shows high mechanical losses that dominate the dissipation of the test mass [44,45].…”

Section: Mirror Thermal Noisementioning

confidence: 99%

Toward a third generation of gravitational wave observatories

Punturo

Lück

2010

Gen Relativ Gravit

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Large gravitational wave interferometric detectors, like Virgo and LIGO, demonstrated the capability to reach their design sensitivity, but to transform these machines into an effective observational instrument for gravitational wave astronomy a large improvement in sensitivity is required. Advanced detectors in the near future and third generation observatories in slightly more than one decade will open the possibility to perform gravitational wave astronomical observations from the Earth. An overview of the technological progress needed to realize a third generation observatory, like the Einstein Telescope (ET), and a possible evolution scenario are discussed in this paper.

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“…The loss of cooled sapphire (above 4 K), which is the mirror substrate of LCGT, has already been measured [9]. Re- * Electronic address: yamak@icrr.u-tokyo.ac.jp cent theoretical [10,11,12,13,14] and experimental [15,16,17] work has revealed that the loss of the reflective coating on the mirror surface has a large contribution to the thermal noise. The loss of a cooled coating is also an interesting issue in solid state physics (for example, Ref.…”

Section: Introductionmentioning

confidence: 99%

Measurement of the mechanical loss of a cooled reflective coating for gravitational wave detection

et al. 2006

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We have measured the mechanical loss of a dielectric multilayer reflective coating (ion-beam sputtered SiO2 and Ta2O5) in cooled mirrors. The loss was nearly independent of the temperature (4 K ∼ 300 K), frequency, optical loss, and stress caused by the coating, and the details of the manufacturing processes. The loss angle was (4 ∼ 6) × 10 −4 . The temperature independence of this loss implies that the amplitude of the coating thermal noise, which is a severe limit in any precise measurement, is proportional to the square root of the temperature. Sapphire mirrors at 20 K satisfy the requirement concerning the thermal noise of even future interferometric gravitational wave detector projects on the ground, for example, LCGT.

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

Cited by 298 publications

References 26 publications

Cooling-by-measurement and mechanical state tomography via pulsed optomechanics

Cooling-by-measurement and mechanical state tomography via pulsed optomechanics

Toward a third generation of gravitational wave observatories

Measurement of the mechanical loss of a cooled reflective coating for gravitational wave detection

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