Modeling Mode-Locked Bismuth Laser for Soliton Generation in the Normal and Anomalous Dispersion Regime

摘要

A scheme of a passively mode-locked fiber laser that deploys a Bismuth-doped germano-phosphosilicate fiber as an active medium is introduced. It operates at Bismuth amplification maximum of 1320 nm if suitably pumped at 1220 nm. We also introduce a model to describe the nonlinear light propagation in this laser in the regime of normal and anomalous group-velocity dispersion. The model is developed for two polarizations states accounting for a broad range of dynamical regimes connected to the state of cavity polarization. It also includes a low level of amplification in Bismuth. Depending on the level of the gain saturation energy, we observe the formation of stable dissipative solitons or incoherent pulses in the normal cavity group-velocity dispersion regime or the formation of single or two solitons per roundtrip in the anomalous dispersion regime. The results coincide well with already published experimental observations of dynamics in Bismuth lasers at 1320 nm which validates our model. As for the application potential, the introduced laser scheme can be used to effectively treat skin acne and various other medical applications.