1. 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

2. 1 IN A NUTSHELL

3. EXPERIMENTAL LAYOUT SCHEME I 2 2-COLOR LASER

4. EXPERIMENTAL LAYOUT SCHEME I 3

5. SECOND HARMONIC GENERATOR 4 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

6. SHG/SQUEEZER DESIGN 5

7. EFFICIENT SHG 6

8. 7 inferred conversion efficiency > 90%

9. EFFICIENT SHG 8 inferred conversion efficiency > 90% PRELIMINARY

10. EXPERIMENTAL LAYOUT SCHEME II 9

11. EXPERIMENTAL LAYOUT SCHEME III 10

12. EXPERIMENTAL LAYOUT SCHEME IV 11

13. EXPERIMENTAL LAYOUT SCHEME V 12

14. GEO SQUEEZING BREADBOARD Breadboard: 113x135 cm Main Laser: InnoLight Mephisto > 120 opt. components Aux. Lasers: Mephisto OEM total weight ≈ 120 kg 13 Optics: ATF (superpolished) Nonlinear medium: PPKTP Beam height: 50mm Compact design

15. STATUS OF THE EXPERIMENT I 14

16. STATUS OF THE EXPERIMENT II 15

17. STATUS OF THE EXPERIMENT II 16

18. STATUS OF THE EXPERIMENT II 17

19. STATUS OF THE EXPERIMENT II 18

20. 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 19

21. TIMELINE AND SUMMARY Assembling started! Squeezed light injection TIMELINE Spring/Summer 2009 into GEO 600: GOAL Squeezing-improved sensitivity for GEO 600 Test of squeezing as standard tool for future GW detectors 20

22. THANK YOU

23. SPARE SLIDES

24. AUTO-ALIGNMENT SCHEME

25. LOSS BUDGET 5%2%5% 1% 2% Total loss: 20%

26. LOSS BUDGET II Goal: 6 dB detected squeezing

27. SHOT NOISE (DARK FRINGE OPERATION)

28. BACK-ACTION NOISE (SQL) Shot noise Radiation pressure noise [Unruh 1982] [Jaekel, Reynaud 1990] QND- Regime Squeezed Light Input (8dB)