Modelling the sub-100 fs Dy3+: Fluoride fiber laser beyond 3 μm

Generating ultrafast pulses in the mid-infrared (mid-IR) region around 3 mu m is a scientific and technological frontier at present. In this work, we have investigated the sub-100 fs Dy3+: fluoride fiber laser generation beyond 3 mu m regime via the hybrid mode-locking mechanism based on the semiconductor saturable absorber mirror (SESAM) and the nonlinear polarization rotation (NPR) method numerically. Compared with the single SESAMand NPR-based mode-locking, the hybrid mode-locked Dy3+: fluoride fiber laser delivers much shorter pulses via the fast and slow mode-locking from the NPR and SESAM, respectively. When dispersion compensation is taken into the hybrid mode-locking, the ultrafast pulse of 94 fs with a corresponding time-bandwidth product (TBP) of 0.333 is achieved. In addition, laser performance optimizations are investigated. By optimizing the parameters of the gain fiber and SESAM, the shortest pulse duration of 85 fs can be obtained. The results represent a feasible solution and design guidelines for ultrafast mid-infrared fiber laser generation beyond 3 mu m.

Automated summary

In this study, the sub-100 fs Dy3+: fluoride fiber laser generation beyond 3 mu m regime was investigated numerically using a hybrid mode-locking mechanism based on the semiconductor saturable absorber mirror (SESAM) and the nonlinear polarization rotation (NPR) method. Compared with single SESAM and NPR-based mode-locking, the hybrid mode-locked Dy3+: fluoride fiber laser delivered much shorter pulses through fast and slow mode-locking from the NPR and SESAM, respectively. By considering dispersion compensation, an ultrafast pulse of 94 fs with a time-bandwidth product (TBP) of 0.333 was achieved. In addition, laser performance optimizations were investigated, and the shortest pulse duration of 85 fs was obtained. These results provide a feasible solution and design guidelines for ultrafast mid-infrared fiber laser generation beyond 3 mu m.