Properties of normal-dispersion femtosecond fiber lasers

TLDR

Spectral filtering of a chirped pulse in the cavity is a major component of pulse shaping in all‑normal‑dispersion mode‑locked fiber lasers. The study systematically investigates all‑normal‑dispersion mode‑locked fiber lasers, identifying nonlinear phase shift, spectral filter bandwidth, and group‑velocity dispersion as key parameters governing their behavior and properties. The authors analyze how variations in nonlinear phase shift, spectral filter bandwidth, and group‑velocity dispersion affect laser performance, summarizing observed trends. The lasers exhibit a wide range of pulse shapes and evolutions, and experimental Yb‑doped laser data agree reasonably well with numerical simulations.

Abstract

We report a systematic study of all-normal-dispersion mode-locked fiber lasers. Spectral filtering of a chirped pulse in the cavity is a major component of the pulse shaping in these lasers. We identify the nonlinear phase shift accumulated by the pulse, spectral filter bandwidth, and group-velocity dispersion as the key parameters that determine the behavior and properties of these lasers. Trends in the performance as these parameters are varied are summarized. A wide range of pulse shapes and evolutions can occur. Experimental results from Yb-doped all-normal-dispersion fiber lasers agree reasonably well with the results of numerical simulations.