J R Smith et al 2008 Class. Quantum Grav. 25 035003 doi:10.1088/0264-9381/25/3/035003
J R Smith1,2, J Degallaix1, A Freise3, H Grote1, M Hewitson1, S Hild1,3, H Lück1, K A Strain4 and B Willke1
Show affiliationsThis paper describes measurements and simulations related to power fluctuations of the laser light in the GEO 600 laser-interferometric gravitational wave detector. Measurements of the relative fluctuations of the light power at three different ports of the main interferometer are presented. In addition, measurements and simulations of the coupling transfer functions from power fluctuations at the input laser to these ports are shown. The transfer function from the input laser to the output port of the interferometer is found to be non-trivial. Despite this, the numerical simulation produces an excellent match to it and gives insight to the mechanisms leading to the complicated shape. Furthermore, the coupling transfer functions of power fluctuations to the main (heterodyne) detector outputs are measured and simulated. These are used to evaluate the level with which laser power fluctuations contribute to the overall noise level of the instrument.
04.80.Nn Gravitational wave detectors and experiments
42.60.Mi Dynamical laser instabilities; noisy laser behavior
78A60 Lasers, masers, optical bistability, nonlinear optics (See also 81V80)
Instrumentation and measurement
Issue 3 (7 February 2008)
Received 4 September 2007, in final form 30 November 2007
Published 14 January 2008
J R Smith et al 2008 Class. Quantum Grav. 25 035003
John C. Collins and Xiaomin Zu JHEP06(2002)018
I V Litvinyuk et al 2008 New J. Phys. 10 083011
Dominic Brecher et al JHEP04(2005)004
Marco Krohn and Michael Flohr JHEP01(2003)020
Alexander Sakhnovich 2008 Inverse Problems 24 025026
Adriaan M H van der Veen et al 2007 Metrologia 44 08003
G Ratel et al 2006 Metrologia 43 06001
Corrado Appignani and Roberto Casadio JCAP06(2008)014
G Ratel et al 2006 Metrologia 43 06006