First characterization of silicon crystalline fibers produced with the μ-pulling technique for future gravitational wave detectors

The design of the gravitational wave interferometric detectors of third generation is under way. An overall improvement of the detector performance can be obtained by reducing a few noise sources, such as seismic noise, shot noise, and most importantly thermal noise. We report here on the design and fabrication of low thermal-noise suspensions made of a new material presently under investigation. An ad hoc technique to produce crystalline silicon fibers has been developed; the first measurements of the fiber mechanical and thermal properties at room temperature have been performed and interpreted. Preliminary measurements of the mechanical losses at low temperature are also discussed.