Alexander Khalaidovski, Henning Vahlbruch, Hartmut Grote, Harald Lück, Benno Willke, Karsten Danzmann and Roman Schnabel

STATUS OF THE GEO HF

SQUEEZED LIGHT SOURCE

LSC-Virgo March 2009 Meeting

Pasadena, March 18th 2009

AEI Hannover

LIGO-G0900232

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IN A NUTSHELL

EXPERIMENTAL LAYOUT SCHEME I

2

2-COLOR LASER

EXPERIMENTAL LAYOUT SCHEME I

3

SECOND HARMONIC GENERATOR

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• Hemilithic cavity

• Nonlinear medium:

• Singly resonant at 1064 nm

• Coupling mirror: R = 90%

• Compact design

1 1.5 10 mm PPKTP crystal

Finesse ≈ 60

• High intrinsic mechanical

x x

stability

SHG/SQUEEZER DESIGN

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EFFICIENT SHG

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EFFICIENT SHG

7

inferred conversion efficiency

> 90%

EFFICIENT SHG

8

inferred conversion efficiency

> 90%

PRELIMINARY

EXPERIMENTAL LAYOUT SCHEME II

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EXPERIMENTAL LAYOUT SCHEME III

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EXPERIMENTAL LAYOUT SCHEME IV

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EXPERIMENTAL LAYOUT SCHEME V

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GEO SQUEEZING BREADBOARD

Breadboard: 113x135 cm

Main Laser: InnoLight Mephisto

> 120 opt. components

Aux. Lasers: Mephisto OEM

total weight ≈ 120 kg

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Optics: ATF (superpolished)

Nonlinear medium: PPKTP

Beam height: 50mm

Compact design

STATUS OF THE EXPERIMENT I

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STATUS OF THE EXPERIMENT II

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STATUS OF THE EXPERIMENT II

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STATUS OF THE EXPERIMENT II

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STATUS OF THE EXPERIMENT II

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ELECTRONIC CONTROL

• Analog electronics for high

• Digitally interfaced

• Real time LINUX

• Operation in

bandwidth control loops

control system (EPICS)

24 h/day, 7 days/week self-relocking mode

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TIMELINE AND SUMMARY

• Assembling started!

• Squeezed light injection

TIMELINE

Spring/Summer 2009

into GEO 600:

GOAL

• Squeezing-improvedsensitivity for GEO 600

• Test of squeezing as standard toolfor future GW detectors

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THANK YOU

SPARE SLIDES

AUTO-ALIGNMENT SCHEME

LOSS BUDGET

5% 2% 5%

1%

1%1%

1%

1%

2% 2%

Total loss: 20%

LOSS BUDGET II

Goal:

6 dB detected squeezing

SHOT NOISE (DARK FRINGE OPERATION)

BACK-ACTION NOISE

(SQL)

Shot noise

Radiation pressure

noise

[Unruh 1982][Jaekel, Reynaud 1990]

QND-Regime

Squeezed Light Input (8dB)

ˆ X 1

ˆ X 2