Characteristics of fibre Bragg gratings and influences on high-power Raman fibre lasers

摘要

In this paper, some characteristics of fibre Bragg gratings (FBGs) written in Raman fibres, such as insertion losses and spectra, are described. Their influences on a typical Raman fibre laser are numerically simulated. The insufficient FBG bandwidth and depth of a weak FBG will cause a significant leakage of the cavity power. Meanwhile, a large insertion loss of a strong FBG will result in a significant cavity loss. Based on this trade-off, the selection of FBG parameters for this kind of Raman fibre laser is discussed. The spectral broadening effect together with its impact on the simulation accuracy is also analysed. The simulated results agree well with the experimental results. The proposed model and obtained results are important for the design and application of high-power Raman fibre lasers. [References: 25]