Transmission of an optical frequency through a 3 km long optical fiber B. de Beauvoir, F. Nez, L. Hilico, L. Julien, F. Biraben, B. Cagnac, J. J. Zondy, D. Touahri, O. Acef and A. Clairon Eur. Phys. J. D, 1 2 (1998) 227-229 Published online: 15 February 1998 DOI: 10.1007/s100530050085