Isolation from seismic motion is vital for vibration sensitive experiments. The seismic attenuation system (SAS) is a passive mechanical isolation system for optics suspensions. The low natural ...frequency of a SAS allows seismic isolation starting below 0.2 Hz. The desired isolation at frequencies above a few hertz is 70-80 dB in both horizontal and vertical degrees of freedom. An introduction to the SAS for the AEI 10 m Prototype, an overview of the mechanical design and a description of the major components are given.
A series of recent articles have presented results demonstrating optical cooling of macroscopic objects, highlighting the importance of this phenomenon for investigations of macroscopic quantum ...mechanics and its implications for thermal noise in gravitational wave detectors. In this Letter, we present a measurement of the off-resonance suspension thermal noise of a 1 g oscillator, and we show that it can be cooled to just 70 mK. The cooling is achieved by using a servo to impose a phase delay between oscillator motion and optical force. A model is developed to show how optical rigidity and optical cooling can be interchangeable using this technique.
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At present a 10 m prototype interferometer facility is being set up at the AEI Hannover. One unique feature of the prototype will be the suspension platform interferometer (SPI). The purpose of the ...SPI is to monitor and stabilize the relative motion between three seismically isolated optical tables. The in-vacuum tables are suspended in an L-shaped configuration with an arm length of 11.65 m. The design goal of the SPI is to stabilize longitudinal differential displacements to a level of 100 pm between 10 mHz and 100 Hz and relative angular noise of 10 nrad in the same frequency band. This paper covers the optical layout, signal processing and design aspects of the SPI, e.g. cross-coupling between the different degrees of freedom and fibre pointing noise are investigated. A simulation is presented which shows that with the chosen optical design of the SPI all degrees of table motion can be sensed in a fully decoupled way.
The AEI 10 m prototype interferometer Goßler, S; Bertolini, A; Born, M ...
Classical and quantum gravity,
04/2010, Volume:
27, Issue:
8
Journal Article, Conference Proceeding
Peer reviewed
Open access
A 10 m Prototype Interferometer facility is currently being set up at the AEI in Hannover, Germany. The Protoype Interferometer will be housed inside a 100 m 3 ultra-high vacuum envelope. Seismically ...isolated optical tables inside the vacuum system will be interferometrically interconnected via a Suspension Platform Interferometer. Advanced isolation techniques will be used, such as inverted pendulums and geometrical anti-spring filters in combination with multiple-cascaded pendulum suspensions, containing an all-silica monolithic last stage. The light source is a 35 W Nd:YAG laser, geometrically filtered by passing it through a photonic crystal fibre and a rigid pre-modecleaner cavity. Laser frequency stabilisation will be achieved with the aid of a high finesse suspended reference cavity in conjunction with a molecular iodine reference. Coating thermal noise will be reduced by the use of Khalili cavities as compound end mirrors. Data acquisition and control of the experiments is based on the AdvLIGO digital control and data system. The aim of the project is to test advanced techniques for GEO 600 as well as to conduct experiments in macroscopic quantum mechanics. Reaching standard quantum-limit sensitivity for an interferometer with 100 g mirrors and subsequently breaching this limit, features most prominently among these experiments. In this article we present the layout and current status of the AEI 10 m Prototype Interferometer project.
Status of the GEO600 detector Lück, H; Hewitson, M; Ajith, P ...
Classical and quantum gravity,
04/2006, Volume:
23, Issue:
8
Journal Article, Conference Proceeding
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