A prototype of the Laser Guide Stars wavefront sensor for the E-ELT multi-conjugate adaptive optics moduleM. Lombini, L. Schreiber, I. Foppiani, G. Bregoli, G. Cosentino, E. Diolaiti, J.-M. Conan and E. Marchetti1st AO4ELT conference - Adaptive Optics for Extremely Large Telescopes, (2010) 05020DOI: https://doi.org/10.1051/ao4elt/201005020