Towards an optical measurement of the Boltzmann constant at the 10-5 level K. Djerroud, C. Daussy, O. Lopez, A. Amy-Klein, S. Briaudeau, Y. Hermier and C. Chardonnet Ann. Phys. Fr., 32 2-3 (2007) 175-178 Published online: 23 May 2008 DOI: 10.1051/anphys:2008036