title: Linewidth and relative intensity noise measurements of longitudinal modes in ultrahigh-speed mode-locked laser diodes.
abstract: The longitudinal linewidth and corresponding relative intensity noise (RIN) of 10- and 40-GHz mode-locked laser diodes are measured for the first time to our knowledge. It is shown that the cavity Q value is a dominant parameter of the linewidth. It is also shown that the linewidth of the individual modes is almost constant. This means that the phase noise of each mode is almost the same in the mode-locked condition. The RIN value is larger for modes that are distant from the center longitudinal mode. This mode dependence is a consequence of the mode partition noise.
authors.affiliation: Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai-shi, Miyagi-ken 980-8577, Japan. kenbz@riec.tohoku.ac.jp
authors.forename: Kentaro
authors.initials: K
authors.lastname: Haneda
authors.forename: Masato
authors.initials: M
authors.lastname: Yoshida
authors.forename: Masataka
authors.initials: M
authors.lastname: Nakazawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Yoh
authors.initials: Y
authors.lastname: Ogawa