Losses estimation in a 300-m filter cavity and quantum noise reduction in the KAGRA gravitational-wave detector
Presented by eleonora CAPOCASA on 2 Feb 2016 from 17:40 to 18:30
Session: Poster session
The sensitivity of the gravitational-wave detector KAGRA, at present under construction, will be limited by quantum noise in a large fraction of its spectrum. The most promising technique to increase the detector sensitivity is the injection of squeezed states of light, where the squeezing angle is rotated by a Fabry-P ́erot filter cavity. One of the main issues in the filter cavity design and realization are the optical losses given by the mirror surface imperfections. We present a study of the specifications for the mirrors to be used in a 300-m filter cavity for the KAGRA detector. A prototype of the cavity will be constructed at National Astronomical Observatory of Japan (NAOJ), in the infrastructure of the former TAMA interferometer. We also discuss the potential improvement of the KAGRA sensitivity, based on a model of various realistic sources of losses and their influence on the squeezing amplitude. The results of this work can be easily extended to any gravitational-wave interferometric detector planning the use of filter cavities with length of several hundreds of meters.