Transient-fiber-Bragg grating spectra in self-swept Fabry-Perot fiber lasers

摘要

Fiber laser instabilities may significantly influence fiber laser performance. Recently, we have shown that the self-Q-switching instability mode can evolve from the so-called self-induced laser line sweeping (SLLS). The SLLS effect is characterized by quasiperiodic laser line drift in a relatively broad wavelength interval. The SLLS is caused by standing-wave in the cavity. Such regular standing waves series create also significant reflection grating through resonant index change of the rare-earth doped core. We show analysis of the transient gratings spectra, including the effect of superimposed gratings. The numerical model of the fiber laser accounts for the effect of the fiber coiling and twisting on the pump absorption along the active fiber.