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arXiv · 0802.4118

A Quantum-Enhanced Prototype Gravitational-Wave Detector

Keisuke Goda·Osamu Miyakawa·Eugeniy E. Mikhailov·Shailendhar Saraf·Rana Adhikari·Kirk McKenzie·Robert Ward·Steve Vass·Alan J. Weinstein·Nergis Mavalvala
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Abstract

The quantum nature of the electromagnetic field imposes a fundamental limit on the sensitivity of optical precision measurements such as spectroscopy, microscopy, and interferometry. The so-called quantum limit is set by the zero-point fluctuations of the electromagnetic field, which constrain the precision with which optical signals can be measured. In the world of precision measurement, laser-interferometric gravitational wave (GW) detectors are the most sensitive position meters ever operated, capable of measuring distance changes on the order of 10^-18 m RMS over kilometer separations caused by GWs from astronomical sources. The sensitivity of currently operational and future GW detectors is limited by quantum optical noise. Here we demonstrate a 44% improvement in displacement sensitivity of a prototype GW detector with suspended quasi-free mirrors at frequencies where the sensitivity is shot-noise-limited, by injection of a squeezed state of light. This demonstration is a critical step toward implementation of squeezing-enhancement in large-scale GW detectors.

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Keisuke Goda, Osamu Miyakawa, Eugeniy E. Mikhailov, Shailendhar Saraf, Rana Adhikari, Kirk McKenzie, Robert Ward, Steve Vass, Alan J. Weinstein, Nergis Mavalvala. 2008-02-28. A Quantum-Enhanced Prototype Gravitational-Wave Detector. https://doi.org/10.1038/nphys920

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