Audio-Band Frequency-Dependent Squeezing for Gravitational-Wave Detectors
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Published on: May 11, 2014
Eric Oelker1, Tomoki Isogai1, John Miller1
1Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Abstract:
Quantum vacuum fluctuations impose strict limits on precision displacement measurements, those of interferometric gravitational-wave detectors among them. Introducing squeezed states into an interferometer's readout port can improve the sensitivity of the instrument, leading to richer astrophysical observations. However, optomechanical interactions dictate that the vacuum's squeezed quadrature must rotate by 90° around 50 Hz. Here we use a 2-m-long, high-finesse optical resonator to produce frequency-dependent rotation around 1.2 kHz. This demonstration of audio-band frequency-dependent squeezing uses technology and methods that are scalable to the required rotation frequency and validates previously developed theoretical models, heralding application of the technique in future gravitational-wave detectors.
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