Preliminary investigation on a passive method for parametric instability control in advanced gravitational wave detectors

Abstract

In this paper, we propose a passive method to suppress parametric instabilities. This method requires the design of a test mass mirror with appropriate loss distribution. We show that localized losses can significantly reduce the parametric gain without degrading the thermal noise for the advanced LIGO configuration. The method can be use individually or in conjunction with other active feed-back methods. We present numerical analysis for both spherical and non-spherical mirrors. © 2006 IOP Publishing Ltd.