2012/05/24 by Kiwamu Izumi, Koji Arai, K. Arai +22
Engineering · Physics and Astronomy · #Advanced Frequency and Time Standards #Astronomical interferometer #Atom interferometer #Computer science #Electronic engineering #Engineering #Geophysics and Sensor Technology #Gravitational wave #Interferometry #Laser #Lock (firearm) #Metrology #Noise (video) #Optics #Physics #Pulsars and Gravitational Waves Research #Quantum mechanics #Reliability (semiconductor) #Sensitivity (control systems) #astro-ph.IM #gr-qc #physics.optics
paper · pdf · doi:10.1364/josaa.29.002092
published as JOSA A, Vol. 29, Issue 10, pp. 2092-2103 (2012)
arxiv created 2012/05/24 · openalex publication_date 2012/09/12 · arxiv updated 2013/07/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Long-baseline laser interferometers used for gravitational-wave detection have proven to be very complicated to control. In order to have sufficient sensitivity to astrophysical gravitational waves, a set of multiple coupled optical cavities comprising the interferometer must be brought into resonance with the laser field. A set of multi-input, multi-output servos then lock these cavities into place via feedback control. This procedure, known as lock acquisition, has proven to be a vexing problem and has reduced greatly the reliability and duty factor of the past generation of laser interferometers. In this article, we describe a technique for bringing the interferometer from an uncontrolled state into resonance by using harmonically related external fields to provide a deterministic hierarchical control. This technique reduces the effect of the external seismic disturbances by 4 orders of magnitude and promises to greatly enhance the stability and reliability of the current generation of gravitational-wave detectors. The possibility for using multicolor techniques to overcome current quantum and thermal noise limits is also discussed.