1202.3558 (Takashi Uchiyama et al.)

Reduction of thermal fluctuations in a cryogenic laser interferometric
gravitational wave detector    [PDF]

Takashi Uchiyama, Shinji Miyoki, Souichi Telada, Kazuhiro Yamamoto, Masatake Ohashi, Kazuhiro Agatsuma, Koji Arai, Masa-Katsu Fujimoto, Tomiyoshi Haruyama, Seiji Kawamura, Osamu Miyakawa, Naoko Ohishi, Takanori Saito, Takakazu Shintomi, Toshikazu Suzuki, Ryutaro Takahashi, Daisuke Tatsumi

The thermal fluctuation of mirror surfaces is the fundamental limitation for
interferometric gravitational wave (GW) detectors. Here, we experimentally
demonstrate for the first time a reduction in a mirror's thermal fluctuation in
a GW detector with sapphire mirrors from the Cryogenic Laser Interferometer
Observatory at 17\,K and 18\,K. The detector sensitivity, which was limited by
the mirror's thermal fluctuation at room temperature, was improved in the
frequency range of 90\,Hz to 240\,Hz by cooling the mirrors. The improved
sensitivity reached a maximum of $2.2 \times
10^{-19}\,\textrm{m}/\sqrt{\textrm{Hz}}$ at 165\,Hz.

View original: http://arxiv.org/abs/1202.3558