1. GEO600 Detector Status Harald Lück Max-Planck Institut für Gravitationsphysik Institut für Atom- und Molekülphysik, Uni Hannover

2. Worldwide Interferometer Network

3. Laser Optical Layout Michelson Interferometer Output Mode Cleaner Mode Cleaners 600m 10 W 5 W 1 W ~ 5 kW 10 kW at Beam Splitter ~50mW Light power (specs)

4. GEO 600 Sensitivity specs.

6. Laser Light Power (current) Michelson Interferometer Output Mode Cleaner Mode Cleaners 10W 1W 300W at Beam Splitter 2W2W ~10mW Mode Cleaners: Troughput 80% 72% Finesse 2700 1900 Visibility 96% 92% 98.65% Power Recycling Cavity: Mode matching97% Finesse 450 Linewidth 270 Hz

7. Optical Layout Main Interferometer Mode Cleaner Laser Bench Output Bench

8. Slave Master Slave entrance to vacuum system Laser System Master Laser: Nd:YAG NPRO (non-planar ring oscillator) 800mW @ 1064 nm Slave Laser: Nd:YAG injection-locked ring cavity 14 W @ 1064nm less than 5% in higher modes Additional Information: Talk: Wednesday 12:40 – 13:10 h Benno Willke Poster session: Tuesday 20:30 – 22:00 h

9. GEO Triple Pendulum Suspension

10. Thermal Noise Issues  Monolithic Suspension Silicate (Hydroxy- Catalysis) Bonding Weld

11. Length and Frequency Control Michelson Interferometer Output Mode Cleaner Laser Mode Cleaners 25 MHz 13 MHz 37 MHz Laser Frequency Stabilisation: no rigid reference cavity laser is directly stabilised to suspended cavities 3 sequential Pound- Drever-Hall control loops common mode of the Power-Recycled Michelson serves as frequency reference

12. Mode Cleaners Output Mode Cleaner Michelson Length Control Michelson Interferometer Laser 15 MHz 10 MHz Differential arm length: (gravitational wave signal) heterodyne detection Schnupp modulation Signal-Recycling control: separate modulation frequency reflected beam from beam splitter AR coating

13. Reaction Pendulum: 3 coil-magnet actuators at intermediate mass Electrostatic actuation on test mass bias 500V, range 0-800V=4µm Test Mass Actuators <10Hz >10Hz

14. Alignment Control differential wave-front sensing spot position control 4 degrees of freedom at MC 1 +4 at MC 2 +4 at MI (common mode) +2 at MI (differential mode) +2 at Signal-Recycling cavity 16 + 20 = 36 Alignment Control

15. Magnet/coil actuators on IM UGF: ~10Hz Diff. MI Fast Auto-Alignment Output port  Reduces misalignment below 50 nrad rms  Reliable locking over long timescales. Duty cycle >95%

16. Output mode Radii Of Curvature of folding mirrors do not match East ROC: 687m North ROC: 666m Spec: 640m

17. Thermal adjustment of ROC + -

18. Thermal adjustment of ROC (II)

20. 15 W 10 W

21. 15 W 20 W

22. 15 W 30 W

23. 15 W 40 W

24. 15 W 50 W

25. 15 W 50 W

26. 15 W 60 W

27. 15 W 70 W

28. Signal Recycling Mirror Reflectivity = 99% Coil/magnet actuation directly to mirror Triple pendulum suspension with reaction pendulum chain Tunable between 550Hz and 5kHz Mode-healing 2x

29. Signal Recycling Mirror Reflectivity = 99% Coil/magnet actuation directly to mirror Triple pendulum suspension with reaction pendulum chain Tunable between 550Hz and 5kHz Mode-healing 5 kHz3 kHz 1 kHz

30. Sensitivity Development Dec. 2001 Aug. 2002 Nov. 2003 Jan. 2004 78% 98.5% 95.2% 98.7%