Dispersion Managed Mode-Locking in All-Fiber Er-Doped Fiber Laser with Oam Output Based on Mode Superposition

Abstract

We present and demonstrate experimentally the dispersion managed mode-locking pulse generation in Er-doped fiber laser at around 1560 nm wavelength in this work. The linear cavity laser scheme is implemented with the all-fiber ring serving as a total reflection mirror and semiconductor saturable absorber mirror (SESAM) as the mode-locker and the non-transparent mirror. The dispersion compensation is applied to change the net dispersion from anomalous to normal dispersion, which allows us to integrate mode-locked regimes in the -0.495 ps2~+0.197 ps2 net-cavity-dispersion range by incorporating the different lengths of Dispersion Compensating Fiber (DCF) in laser cavity. The noise-like mode-locked pulse, the conventional soliton and high order harmonic mode-locked pulse are observed during the net cavity dispersion variation process. In addition, the homemade mode selection couplers (MSC) with high order modes emission (LP11, LP21, LP31) are utilized to realize the high mode purity OAM output based on mode superposition principle in the fiber laser.

Keywords: All-fiber laser, Mode-locked regimes, Dispersion management, OAM, Mode superposition