Title :
Thermal noise measurements on micro-cantilevers coated with dielectric materials
Author :
Cagnoli, Gianpietro ; Dolique, V. ; Degallaix, Jerome ; Flaminio, R. ; Forest, Daniele ; Granata, Massimo ; Michel, Cotsaftis ; Morgado, Nazario ; Pinard, L. ; Aguilar, Fernando J. ; TianJun Li ; Geitner, Mickael ; Bellon, Ludovic
Author_Institution :
Lab. des Mater. Avances, Univ. Claude Bernard Lyon I, Villeurbanne, France
Abstract :
In recent years an increasing number of devices and experiments are shown to be limited by mechanical thermal noise. In particular sub-Hertz laser frequency stabilization and gravitational wave detectors, that are able to measure fluctuations of 10-18 m/√(Hz) or less, are being limited by thermal noise in the dielectric coatings deposited on mirrors. We present a novel technique of structural relaxation analysis based on the direct thermal noise measurements on micro-cantilevers and we compare it with the results obtained from the mechanical loss measurements. The dielectric coatings are deposited by ion beam sputtering. The results presented here give a loss angle of annealed tantala and as-deposited silica coatings of (3.9 ± 0.4)·10-4 and (5.8 ± 1.0)·10-4 respectively, from 10 Hz to 20 kHz.
Keywords :
annealing; cantilevers; coatings; dielectric materials; frequency stability; gravitational wave detectors; ion beams; loss measurement; microsensors; mirrors; sputtering; thermal noise; thermal variables measurement; annealed tantala; as-deposited silica coatings; dielectric coatings; dielectric materials; fluctuations; frequency 10 Hz to 20 kHz; gravitational wave detectors; ion beam sputtering; mechanical loss measurements; mechanical thermal noise; microcantilever coating; mirrors; structural relaxation analysis; subHertz laser frequency stabilization; thermal noise measurements; Coatings; Noise; Noise measurement; Resonant frequency; Silicon compounds; Temperature measurement; Thermal noise;
Conference_Titel :
Noise and Fluctuations (ICNF), 2013 22nd International Conference on
Conference_Location :
Montpellier
Print_ISBN :
978-1-4799-0668-0
DOI :
10.1109/ICNF.2013.6578891