Dispersion Managed Mode-locking in all-fiber Polarization-maintaining Nd-doped Laser at 920 nm

TL;DR

This paper demonstrates dispersion managed mode-locking in an all-fiber Nd-doped laser at 920 nm, achieving high-order harmonic mode-locking and near-parabolic pulse operation through dispersion control and numerical optimization.

Contribution

It introduces a novel dispersion management scheme in a polarization-maintaining fiber laser at 920 nm, combining experimental and numerical methods to optimize ultrashort pulse generation.

Findings

Achieved high-order harmonic mode-locking near zero dispersion.

Demonstrated large energy span with near-parabolic pulses.

Validated numerical simulations for laser design optimization.

Abstract

We present a comprehensive study of dispersion managed ultrashort-pulse generation in Nd-doped polarization maintaining all-fiber laser at a 920 nm wavelength. We implement a linear laser scheme with a chirped fiber Bragg grating (CFBG) serving as a semitransparent mirror and semiconductor saturable absorber mirror (SESAM) as a mode-locker and as a second non-transparent mirror. Complete 1064 nm emission filtering is ensured by 920/1064 wavelength division multiplexer. The dispersion compensation by CFBG was sufficient to reach anomalous net dispersion in the shortest laser scheme allowing us to investigate mode-locking regimes in the -0.05 ps 2 - 0.24 ps 2 net dispersion range by varying the length of the passive fiber. With this approach we demonstrate high order harmonic mode-locking at dispersion closer to zero and large energy span near-parabolic shape single pulse operation in anomalous dispersion regime. The investigation is supported by numerical simulations used to optimize the laser resonator design and to investigate intracavity pulse evolution.