Large Petermann factor in chaotic cavities with many scattering channels K. M. Frahm, H. Schomerus, M. Patra and C. W. J. Beenakker Europhys. Lett., 49 1 (2000) 48-54 Published online: 01 September 2002 DOI: 10.1209/epl/i2000-00118-y