Katrin Dahl for the AEI 10 m Prototype teamMarch 2010 – DPG Hannover Q29.1

http://10m-prototype.aei.uni-hannover.de

Stabilising the distance of 10 m separated optical tables to 100 pm/sqrt(Hz)

AEI 10m Prototype

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Prototype hall

11.65 m

11.6

5 m

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For details on tables see talk

Q29.4Residual table motion

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Longitudinal motion stabilised

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Relative table motion stabilised

Why distance stabilisation of tables?

The AEI 10 m Prototype will provide ultra-low displacement noise testing environment• To probe at (and later go beyond) the standard quantum limit • Entanglement of macroscopic test masses• For GRACE follow-on and LISA related experiments • ...

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For details see talk Q29.5

(Homodyne) Mach-Zehnder interferometry

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Heterodyne Mach-Zehnder interferometry

• No specific lock point Enables to track table

motion over more than one wavelength

• Control bandwidth 100 Hz heterodyne frequency

of about 19 kHz

• Use of in-house knowledge (LISA Pathfinder technology)

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Optical layout

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• Heterodyne Mach-Zehnder IFOs with unequal arm lengths (by 23m)

• Stable laser required to reach design sensitivity of 100 pm/sqrt(Hz)@10 mHz – iodine stabilized Nd:YAG

Optical layout

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• Thermal drifting requires components to be bonded onto a Clearceram (CTE=0.4*10-7/K) baseplate by hydroxide-catalysis bonding technique.

• Beam height 45 mm

• Use of quadrant photodiodes

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4 Interferometers

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Monitoring of • power fluctuations• beam pointing

Power monitor

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Reference IFO

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Diagnostic IFO

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West IFO

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South IFO

Test setup

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Optical layout

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Longitudinal displacement

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Pitch

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Yaw

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Blind test

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Thank you for your attention http://10m-prototype.aei.uni-hannover.de