We report the passive mode-locking at harmonics of the free spectral range (FSR) of the intracavity multichannel filter in a fiber ring laser. The laser uses a sampled fiber Bragg grating (SFBG) with a free spectral range (FSR) of 0.8 nm, or 99 GHz at 1555 nm, and a length of highly nonlinear photonic crystal fiber with low and flat dispersion. Stable picosecond soliton pulse trains with twofold to sevenfold enhancement in the repetition rate, relative to the FSR of the SFBG, have been achieved. The passive mode-locking mechanism that is at play in this laser relies on a dissipative four-wave mixing process and switching of repetition rate is realized simply by adjustment of the intracavity polarization controllers.
© 2005 Optical Society of America
(060.5530) Fiber optics and optical communications : Pulse propagation and temporal solitons
(140.3500) Lasers and laser optics : Lasers, erbium
(190.7110) Nonlinear optics : Ultrafast nonlinear optics
(320.7090) Ultrafast optics : Ultrafast lasers
Fiber Optics and Optical Communications
Shumin Zhang, Fuyun Lu, Xinyong Dong, Ping Shum, Xiufeng Yang, Xiaoqun Zhou, Yandong Gong, and Chao Lu, "Passive mode locking at harmonics of the free spectral range of the intracavity filter in a fiber ring laser," Opt. Lett. 30, 2852-2854 (2005)