Quantum Optics Technique Significantly Enhances Sensitivity of Gravitational Wave Detectors

## Quantum Optics Technique Significantly Enhances Sensitivity of Gravitational Wave Detectors

[Quieting Noise in Gravitational-Wave Detectors](https://physics.aps.org/articles/v16/189?utm_campaign=physics&utm_medium=social&utm_source=reddit) – Physics Magazine Article

PRX Research Article – https://journals.aps.org/prx/abstract/10.1103/PhysRevX.13.041021?utm\_campaign=prj-promo&utm\_medium=social&utm\_source=reddit&utm\_term=ligo-oct-30

The LIGO Scientific Collaboration has demonstrated a noise-squeezing technique for the entire range of gravitational frequencies LIGO can detect—a feat that could boost the detection rate of black hole mergers by up to 65%.

The Laser Interferometer Gravitational-Wave Observatory (LIGO) collaboration achieved a significant improvement in their detector sensitivity by implementing a technique called frequency-dependent squeezing.

The technique originated from quantum optics research two decades ago. After much effort, researchers were able to successfully scale the technique up to the hundred-meter scales required for application in gravitational wave detectors and apply it to the LIGO detectors.

Frequency-dependent squeezing let the researchers counteract a source of noise called measurement back-action noise in the LIGO detectors for the first time. The achievement significantly reduces the overall quantum noise in the detectors over a broad range of frequencies and could increase the detection rate of astrophysical events by up to 65%.

The technique has enabled the sensitivity of the current LIGO O4 observing run that began in May. The Virgo and KAGRA gravitational-wave detectors could also be improved in a future upgrade, further enhancing the sensitivity of gravitational-wave searches.

“Broadband Quantum Enhancement of the LIGO Detectors With Frequency-Dependent Squeezing” was published in Physical Review X on Oct. 30. Images for the LIGO study may be used with attribution.