APS: Squeezing More from Gravitational-Wave Detectors
Posted: Tue Dec 10, 2019 9:45 pm
Squeezing More from Gravitational-Wave Detectors
Physics Focus | American Physical Society | 2019 Dec 05
New Instrument Extends LIGO's Reach
Massachusetts Institute of Technology | 2019 Dec 05
Squeezed Light Success at Virgo
Albert Einstein Institute | 2019 Dec 05
Quantum-Enhanced Advanced LIGO Detectors in the Era of Gravitational-Wave Astronomy ~ M. Tse et al
via the Application of Squeezed Vacuum States of Light ~ Virgo Collaboration, F. Acernese et al
Physics Focus | American Physical Society | 2019 Dec 05
New hardware installed in current gravitational-wave detectors uses quantum effects to boost sensitivity and increase the event detection rate by as much as 50%.
Since 2015, gravitational-wave detections have become routine in the two US-based Advanced LIGO instruments and in the Virgo detector in Italy, opening a new window in astronomy. The LIGO and Virgo collaborations have now demonstrated—in separate papers—a modification to their detectors that uses quantum physics to suppress random noise in the signal. The scheme improves the sensitivity of both instruments, which will boost the expected rate of detections by 20 to 50%.
Advanced LIGO and Virgo use interference of laser light bouncing back and forth along two perpendicular arms, 3–4 km long, to detect the spacetime ripples from a passing gravitational wave. The detector sensitivity — which corresponds to space distortions of close to 10−20m — is limited by the effects of so-called quantum noise in the photons. Each photon in the light beam experiences quantum fluctuations, which affects its time of arrival after a round trip along the arms. “The photons arrive ‘on time’ at the detector on average, but some are very early and some are very late, forming a wide bell curve,” says Maggie Tse ... The detectors are only sensitive to a gravitational wave if it changes the travel time in one arm by more than the width of this bell curve.
The LIGO and Virgo teams have reduced this noise using quantum squeezing—an idea first suggested nearly 40 years ago by quantum physicist Carlton Caves [1]. Quantum squeezing makes the arrival-time bell curve narrower, so that the photon fluctuations mask fewer of the gravitational-wave signals. A few prototype demonstrations have previously shown that squeezing can reduce noise in gravitational-wave detection [2, 3], and it has been used for several years at the GEO600 detector operated by the Albert Einstein Institute (AEI) in Germany [4]. ...
New Instrument Extends LIGO's Reach
Massachusetts Institute of Technology | 2019 Dec 05
Squeezed Light Success at Virgo
Albert Einstein Institute | 2019 Dec 05
Quantum-Enhanced Advanced LIGO Detectors in the Era of Gravitational-Wave Astronomy ~ M. Tse et al
- Physical Review Letters 123(23):1107 (06 Dec 2019) DOI: 10.1103/PhysRevLett.123.231107
via the Application of Squeezed Vacuum States of Light ~ Virgo Collaboration, F. Acernese et al
- Physical Review Letters 123(23):1108 (06 Dec 2019) DOI: 10.1103/PhysRevLett.123.231108