1. Generation and Control of Squeezed Light Fields R. Schnabel  S.  Chelkowski  A.  Franzen  B.  Hage  H.  Vahlbruch  N. Lastzka  M.  Mehmet  J.  DiGuglielmo  und  K. Danzmann  Albert-Einstein-Institut  Hannover  Max-Planck-Institut für  Gravitationsphysik  und  Institut für Gravitationsphysik, Universität Hannover

2. Elba, 28.05.2006, Roman Schnabel 2 Techniques against Shot Noise Power- Recycling mirror Laser Photo diode RSE / Signal-recycling mirror Arm cavity Vacuum (shot) noise Squeezed vacuum !

3. Elba, 28.05.2006, Roman Schnabel 3 Phase Modulation at  0        (    2 )

4. Elba, 28.05.2006, Roman Schnabel 4 Amplitude Modulation at  0      

5. Elba, 28.05.2006, Roman Schnabel 5 Amplitude Squeezing at  0       Quantum noise Improved signal to noise ratio

6. Elba, 28.05.2006, Roman Schnabel 6 Standard design of a squeezed field source, (Optical parametric amplifier, resonator with MgO:LiNbO 3 -medium)  Length,   LO,    Generation of Squeezed Fields Pump field, cw, 532nm Squeezed field, cw, 1064nm Crystall

7. Elba, 28.05.2006, Roman Schnabel 7 Optical Parametric Amplification   Generation of phase squeezed light (g 1/2 =2)

8. Elba, 28.05.2006, Roman Schnabel 8 Optical Parametric Amplification Generation of amplitude squeezed light (by deamplification, g 1/2 =1/2)  

9. Elba, 28.05.2006, Roman Schnabel 9 “Squeezing” and Signal-Recycling Power- Recycling mirror Laser Photo diode Signal-recycling mirror Faraday rotator SHG OPA GEO 600 topology

10. Elba, 28.05.2006, Roman Schnabel 10 “Squeezing” and Signal-Recycling Vacuum (a) Squeezed vacuum + signal (b) Signals (c)

11. Elba, 28.05.2006, Roman Schnabel 11 Generation of Squeezed Fields Technical laser noise Shot noise Detector dark noise Squeezed noise

12. Elba, 28.05.2006, Roman Schnabel 12 Control of Squeezed Vacuum Fields Carrier Light is not allowed !

13. Elba, 28.05.2006, Roman Schnabel 13 P-pol for OPO length control Frequency shifted field that still senses parametric amplification Control of Squeezed Vacuum Fields General concept: Use coherent but not interfering control fields: Frequency shifted fields Carrier Light is not allowed ! First audio-band squeezing: [McKenzie et al., PRL 93, 161105 (2004)] New experiment !

14. Elba, 28.05.2006, Roman Schnabel 14 Was wir vorhaben:

15. Elba, 28.05.2006, Roman Schnabel 15 Squeezing in the GW Detection Band 4 dB squeezing (a)Shot noise, 88   W(c) Shot noise, double laser power (b)Squeezed noise(d) Shot noise, half laser power [Vahlbruch et al., submitted (2006), available as LSC reviewed manuscript]

16. Elba, 28.05.2006, Roman Schnabel 16 Squeezing in the GW Detection Band [Vahlbruch et al., submitted (2006), available as LSC reviewed manuscript]

17. Elba, 28.05.2006, Roman Schnabel 17

18. Elba, 28.05.2006, Roman Schnabel 18 Squeezing in the GW Detection Band (a)Shot noise (b)Squeezed noise

19. Elba, 28.05.2006, Roman Schnabel 19 Summary Squeezed field injection is fully compatible with detuned signal recycling and a possible control scheme has been demonstrated (in the MHz regime). A control scheme for squeezed vacuum fields has been demonstrated which enabled the observation of squeezing from 10 Hz to 10 kHz.