title: Audio-Band Frequency-Dependent Squeezing for Gravitational-Wave Detectors.
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.
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Oelker
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Isogai
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: John
authors.initials: J
authors.lastname: Miller
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Maggie
authors.initials: M
authors.lastname: Tse
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Barsotti
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Nergis
authors.initials: N
authors.lastname: Mavalvala
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Evans