Coherent phonon frequency comb generated by few-cycle femtosecond pulses in Si Muneaki Hase, Masayuki Katsuragawa, Anca Monia Constantinescu and Hrvoje Petek EPJ Web of Conferences, 41 (2013) 04020 Published online: 13 March 2013 DOI: 10.1051/epjconf/20133104020