Double optical spring enhancement for gravitational wave detectors
Abstract
Currently planned second-generation gravitational-wave laser interferometers such as Advanced LIGO exploit the extensively investigated signal-recycling (SR) technique. Candidate Advanced LIGO configurations are usually designed to have two resonances within the detection band, around which the sensitivity is enhanced: a stable optical resonance and an unstable optomechanical resonance - which is upshifted from the pendulum frequency due to the so-called optical-spring effect. Alternative to a feedback control system, we propose an all-optical stabilization scheme, in which a second optical spring is employed, and the test mass is trapped by a stable ponderomotive potential well induced by two carrier light fields whose detunings have opposite signs. The double optical spring also brings additional flexibility in re-shaping the noise spectral density and optimizing toward specific gravitational-wave sources. The presented scheme can be extended easily to a multi-optical-spring system that allows further optimization.
Cite
@article{arxiv.0805.3096,
title = {Double optical spring enhancement for gravitational wave detectors},
author = {Henning Rehbein and Helge Mueller-Ebhardt and Kentaro Somiya and Stefan L. Danilishin and Roman Schnabel and Karsten Danzmann and Yanbei Chen},
journal= {arXiv preprint arXiv:0805.3096},
year = {2009}
}