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Progress toward squeeze injection in Enhanced LIGO

Gravitational wave detectors. Progress toward squeeze injection in Enhanced LIGO. Squeeze-enhanced AdLIGO. Nergis Mavalvala @ LVC, September 2009. LIGO-G0900849-00. Advanced LIGO with squeeze injection. Radiation pressure. Shot noise. Power higher by 4x OR 6 dB squeeze injection. X 2.

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Progress toward squeeze injection in Enhanced LIGO

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  1. Gravitational wavedetectors Progress toward squeeze injection in Enhanced LIGO Squeeze-enhancedAdLIGO Nergis Mavalvala @ LVC, September 2009 LIGO-G0900849-00

  2. Advanced LIGO with squeeze injection Radiation pressure Shot noise Power higher by 4x OR 6 dB squeeze injection

  3. X2 X1 X2 Shot noise limited  (number of photons)1/2 Arbitrarily below shot noise X1 X2 X2 Vacuum fluctuations Squeezed vacuum X1 X1 Quantum Noise in an Interferometer Radiation pressure noise Quantum fluctuations exert fluctuating force  mirror displacement Laser

  4. Squeezed state generation

  5. How to squeeze? • My favorite way • A tight hug

  6. Squeezing injection Second harmonic generator (SHG) • Convert 1064 nm  532 nm with ~50% efficiency Optical parametric oscillator (OPO) • Few 100 mW pump field (532 nm) correlatesupper and lower quantum sidebands around carrier (1064 nm)  squeezing Balanced homodyne detector • Beat local oscillator at 1064nm with squeezed field Laser IFO OPO Faraday rotator ASPD SHG

  7. Squeezed injection in LIGO(after S6)

  8. Goals of H1 test • Inject 6 dB of squeezing into the antisymmetric (AS) port of H1 • Measure 3 dB of improved SNR at frequencies where interferometer is shot noise limited • Ensure that no deleterious effects at all other frequencies in detection band • Low noise performance test is remaining critical step to implementation in Advanced LIGO

  9. The H1 squeezer components • Initial LIGO 10 W MOPA pumps… • AEI-designed SHG  300 to 500 mW of 532 nm (green) • ANU-designed and built traveling wave OPO • LIGO-designed and built electronics • Integration and testing at MIT and LHO

  10. Control System Interferometer S0 HomodyneDetector Fiber (PSL) Faraday S4 Laser 0 SHG OPO S3 S1 S5 S2 OMC Auxiliary Laser 1 AS Port Squeezer DC 10

  11. Servo Model • S0Frequency lock Laser 0 to PSL using FSS • S1 Frequency lock Laser 1 (auxiliary ) to Laser 0 using FSS • S2 Phase lock Laser 1 to green light using feedback to PZT & Laser 1 additive offset • S3 Phase lock squeeze angle to AS port light using feedback to PZT & Laser 0 additive offset (LO lock) • S4 Lock SHG to Laser 0 with PDH to cavity PZT • S5 Lock OPO to green with PDH to cavity PZT

  12. Simulink Model Sigg, Dwyer et al. LIGO-T0900325-v1

  13. Servo Model Fiber Stabilization not needed Laser 0 is frequency locked to main interferometer laser (PSL) and phase locked to AS port light

  14. Noise couplings

  15. Noise Model Highlights • Acoustic couplings • Direct back scattering under control • Requirement • OMC has • Require second in-vacuum Faraday • OPO ring topology is very helpful Motion of scatterer Backscatter reflectivity

  16. Noise Model Highlights • Phase noise requirement < 50 mrad rms • Squeeze angle deviation • Remaining RF sidebands transmitted through OMC are important Detected quadrature Anti-squeezeprojection Phase Noise (°) Squeeze angledeviation PCR/PCD

  17. Noise Model Highlights • Other noise couplings • Laser frequency noise not important due to large servo bandwidth (500 kHz) • Path length variations not important due to large servo bandwidth (few kHz) • Shot noise: 1 mW per detector should be enough • OPO length fluctuations are not suppressed by Local Oscillator (LO) servo

  18. ANU Traveling Wave OPO PZT Actuator Squeezing Out Pump light In Oven/ Temperature Sensor Crystal 150 mm 200 mm 18

  19. ANU OPO Squeezing Performance Electronics Mains harmonics Cross coupling from Coherent Lock Quantum noise • Electronic Noise? Lab environment Acoustic Noise 6dB Observed squeezing 8dB Inferred squeezing H1 Squeezer Status 19

  20. Schedule and Planning • Reviewed, approved and funded (08/2009) • ANU will continue on development of OPO • On track for Spring 2010 delivery • MIT will continue with SHG & laser locking • On track to begin integration with OPO in Spring 2010 • Electronics production at LHO moving forward • RF, PDs, TTFFS and length servos (common mode board) to arrive at MIT December 2009 • Planning for installation in Feb. 2011 • Depends on Advanced LIGO commissioning sequence and S6

  21. Highlights and summary • Outstanding team assembled • Graduate students Sheila Dwyer (MIT), Sheon Chua (ANU) and Michael Stefsky (ANU), Alexander Khalaidovski (AEI) • Led by Daniel Sigg at LHO • Impressive progress on OPO development at ANU • 6 dB of squeezing observed • Traveling wave bowtie design works • Laser, optical table and clean room installed at MIT • AEI loaner SHG at MIT producing green • Entering optimization phase • In the process of building our own (copy of AEI design) • Noise model and simulation done • Electronics design done for RF distribution • Shared with advanced LIGO

  22. GWDetector Laser The End Faraday isolator SHG OPO HomodyneDetector Squeeze Source GW Signal

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