Abstract

Mode-locked fiber laser systems have been interesting research areas for many years, and fiber based mode-locked lasers have found numerous applications in both research and industry. Rare earth doped fibers are well-suited for ultrafast applications as they have a large amplification bandwidth supporting ultrashort pulses and exhibit improved stability and freedom from misalignment. In addition, they offer compact design with inexpensive components and are suitable for high average power applications because their geometry leads to efficient heat dissipation. Non-linear effects are usually quite large in mode-locked fiber lasers, due to the long interaction length with a material, and the tight confinement of the light, but the interplay between dispersion, gain and nonlinearities can also be used to shape the pulse and pulse dynamics, and hence leads to different regimes of mode-locking. The fonnation of the spectral shape of the output pulses is close-to parabolic, and hence lias a close-to parabolic temporal duration (pulses are linearly chirped), in a regime where wave-breaking-free operation is expected. The direct amplification of parabolic pulses allows for the realization of high peak powers without any significant degradation of the recompressed pulse quality [1]. This new mode-locking regime has been observed in a polarization-maintaining (PM)-based fiber laser in a linear cavity configuration where mode locking was achieved using a semiconductor saturable absorber [2]. The linear cavity was made of all PM Yb-doped single mode fibers, thus being intrinsically enviromnental stable. The transmission gratings (TG) were used for dispersion management, and the non-linear mode-locking mechanism was based on a saturable absorber mirror (SAM). In this setup, TG and SAM were placed in the free space section of the cavity. In this contribution, we report the both numerically and experimentally generation of wave-breaking-free pulses from an environmentally stable Yb-doped all-fiber laser. The complete experimental setup is presented in Fig. 1.

© 2007 IEEE