Analysis of gain distribution in cladding-pumped thulium-doped fiber laser and optical feedback inhibition problem in fiber-bulk laser system
Ji En-Cai†, Liu Qiang, Hu Zhen-Yue, Gong Ma-Li
       
Output spectra from FBG1 under different pump currents when OFI problem happens. (a) I = 1.9 A; (b) I = 2.1 A; (c) I = 2.4 A; (d) I = 2.8 A.