Pixelated-core large pitch optical fibre design

Abstract

High power fibre laser system is playing an increasingly important role in today’s industry market. However, further power scaling of it is limited by nonlinear effects and mode instability which occurs at high power intensity. Currently the most effective mitigation strategy is to scale the mode field area, so as to create a dramatic reduction of the guided intensity. However, this will introduce higher order modes (HOMs) and increase the bending loss of the fibre. In this project, a pixelated-core large pitch fibre (LPF) was designed, which has a hexagonal core with Erbium-Ytterbium co-doped filaments. With this design, mode instability at high power level can be avoided, HOMs can be delocalized and bending loss can be suppressed by almost two orders of magnitude. [1st Award]