Quantum expander for gravitational-wave observatories

Mikhail Korobko, Yiqiu Ma, Yanbei Chen, Roman Schnabel
2019 Light: Science & Applications  
The quantum uncertainty of laser light limits the sensitivity of gravitational-wave observatories. Over the past 30 years, techniques for squeezing the quantum uncertainty, as well as for enhancing gravitational-wave signals with optical resonators have been invented. Resonators, however, have finite linewidths, and the high signal frequencies that are produced during the highly scientifically interesting ring-down of astrophysical compact-binary mergers still cannot be resolved. Here, we
more » ... e a purely optical approach for expanding the detection bandwidth. It uses quantum uncertainty squeezing inside one of the optical resonators, compensating for the finite resonators' linewidths while keeping the low-frequency sensitivity unchanged. This quantum expander is intended to enhance the sensitivity of future gravitational-wave detectors, and we suggest the use of this new tool in other cavity-enhanced metrological experiments.
doi:10.1038/s41377-019-0230-2 pmid:31839938 pmcid:PMC6904558 fatcat:wmvzz2wd6bczpcb36wxnqqwhaq