A linearly-polarized passively mode-locked yb-doped fiber laser with nanosecond pulses

Xiaojun Zhu, Guoan Zhang

COMPUTER MODELLING & NEW TECHNOLOGIES 2014 18(12D) 284-288

School of Electronics and Information Nantong University, Nantong City, Jiangsu Province, China, 226019

A linearly-polarized, all-normal dispersion (ANDi), passively mode-locked ytterbium-doped fiber laser is demonstrated with a master oscillator power amplifier (MOPA) structure. Using a cascaded long-period fiber grating as an all-fiber format spectral filter, the modelocked pulse is achieved by nonlinear polarization evolution (NPE) effect. Nanosecond pulses with a low repetition rate of 1.53 MHz and a output power of 363 mW when the seed source after amplifier, and the pulses duration can be tuned from 0.78 ns to 3.57 ns with a polarization extinction ratio of >20 dB. The preliminary experiment shows that the nanosecond pulses output from the ANDi fiber laser could be used as an ideal seed source for all-fiber amplifier system.