Passively mode-locked fiber laser based on symmetrical nonlinear optical loop mirror

Abstract

We propose and demonstrate a passively mode-locked Erbium-doped fiber laser based on symmetrical nonlinear optical loop mirror. The nonlinear optical loop mirror with intensity-depended transmission can act as an equivalent saturable absorber, which results in passively mode-locking of fiber laser. Pulse trains with fundamental cavity frequency and its various harmonic frequencies have been obtained.