LIGO Document P070125-x0
- The Laser Interferometer Gravitational Wave Observatory (LIGO) operates a 40m prototype interferometer on the Caltech campus. The primary mission of the prototype is to serve as an experimental testbed for upgrades to the LIGO interferometers and for gaining experience with advanced interferometric techniques, including detuned resonant sideband extraction (i.e. signal recycling) and dc readout (optical homodyne detection). The former technique will be employed in Advanced LIGO, and the latter in both Enhanced and Advanced LIGO. Using dc readout for gravitational wave signal extraction has several technical advantages, including reduced laser and oscillator noise couplings as well as reduced shot noise, when compared to the traditional rf readout technique (optical heterodyne detection) currently in use in large-scale ground-based interferometric gravitational wave detectors. The Caltech 40m laboratory is currently prototyping a dc readout system for a fully suspended interferometric gravitational wave detector. The system includes an optical filter cavity at the interferometer's output port, and the associated controls and optics to ensure that the filter cavity is optimally coupled to the interferometer. We present the results of measurements to characterize noise couplings in rf and dc readout using this system.
- Full document number: LIGO-P070125-00-Z
- Author(s): Robert Ward; Rana Adhikari; Benjamin Abbott; Rich Abbott; Darcy Barron; Rolf Bork; T Fricke; Valera Frolov; Jay Heefner; Alex Ivanov; Osamu Miyakawa; Kirk Mckenzie; Bram Slagmolen; Michael Smith; Robert Taylor; Steve Vass; Sam Waldman; Alan Weinstein
- Document date: 2007-10-19
- Document received date: 2007-10-19
- Document entry date: 2007-10-19
- Published in Class Quant Grav vol. 25 pg. 114030 (8pp).
DCC Version 3.4.1, contact