title: Arm-length stabilisation for interferometric gravitational-wave detectors using frequency-doubled auxiliary lasers.
abstract: Residual motion of the arm cavity mirrors is expected to prove one of the principal impediments to systematic lock acquisition in advanced gravitational-wave interferometers. We present a technique which overcomes this problem by employing auxiliary lasers at twice the fundamental measurement frequency to pre-stabilise the arm cavities' lengths. Applying this approach, we reduce the apparent length noise of a 1.3 m long, independently suspended Fabry-Perot cavity to 30 pm rms and successfully transfer longitudinal control of the system from the auxiliary laser to the measurement laser.
authors.affiliation: Centre for Gravitational Physics, The Australian National University, Canberra, ACT, 0200, Australia.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Mullavey
authors.forename: Bram J J
authors.initials: BJ
authors.lastname: Slagmolen
authors.forename: John
authors.initials: J
authors.lastname: Miller
authors.forename: Matthew
authors.initials: M
authors.lastname: Evans
authors.forename: Peter
authors.initials: P
authors.lastname: Fritschel
authors.forename: Daniel
authors.initials: D
authors.lastname: Sigg
authors.forename: Sam J
authors.initials: SJ
authors.lastname: Waldman
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Shaddock
authors.forename: David E
authors.initials: DE
authors.lastname: McClelland
mesh_terms: D016477:Artifacts; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006112:Gravitation; D007368:Interferometry / Q000295:instrumentation*; D007834:Lasers; D014159:Transducers