Influence of two-photon absorption on soliton self-frequency shift

In this paper we develop an analytical model for the soliton self-frequency shift, which includes second- and thirdorder dispersion, self-steepening, the full Raman term, and, for the first time to our best knowledge, the effect of two-photon absorption (TPA). We show that TPA can have a significant effect on soliton dynamics in soft-glass materials such as chalcogenides, by severely depleting a soliton and thereby limiting the achievable redshift.

Based on the model, we derive a nonlinear loss length after which the redshift is effectively halted by TPA, which proves to be a useful design tool.