Passive Q-switching dynamics in all-fiber lasers with ring interferometer

摘要

The cooperation of Rayleigh scattering (RS) in fiber interference loop and stimulated Brillouin scattering (SBS) in fiber can change Q factor in resonant cavity .based on which a all-fiber Er-doped Q-switched fiber laser with interference loop is designed. During experiment, the attributes of output laser exploiting interference loops with different coupling ratios and lengths is investigated. A train of pulse laser with pulse duration of 7.2ns, pulse period of 4.709μs, average output power of 5.4mW at pump power of 37mW is obtained which has a good waveform and a peak power fluctuation of: 30%. The results show that interference loop with too high coupling ratio has no contribution to the generation of pulse laser and the coupling ratio of: 10% is suit for it. Even if the coupling ratio of: 10% is chosen, the length of the loop has influence to the attribute of the output laser pulse and the length around 2m is conducive to obtaining good output.