High-sensitivity optical measurement of mechanical Brownian motion Y. Hadjar, P. F. Cohadon, C. G. Aminoff, M. Pinard and A. Heidmann Europhys. Lett., 47 5 (1999) 545-551 Published online: 01 September 2002 DOI: 10.1209/epl/i1999-00422-6