设计了一种双向反馈布里渊-喇曼光纤激光器, 研究了布里渊泵浦对输出特性的影响.布里渊-喇曼光纤激光器由一段7 km色散补偿光纤、1 455 nm喇曼泵浦、可调谐激光器及双反馈环组成.喇曼泵浦功率固定在250 mW, 布里渊泵浦工作波段在喇曼峰值增益处附近, 可得到较多波长数输出.随着布里渊泵浦功率增加, 相邻的布里渊斯托克斯光和经背向瑞利散射的斯托克斯光之间功率差减小, 同时各阶斯托克斯光平均强度增加并达到饱和.受色散补偿光纤中喇曼交叉增益影响, 布里渊泵浦功率由1.8 dBm增加到6.9 dBm, 输出多波长数先增后减.当布里渊泵浦功率为4.4 dBm时, 对应输出波长数最多, 为37个, 波长间隔0.078 nm.

The output characteristic of a new-designed bidirectional feedback Brillouin-Raman fiber with Brillouin pump variation was studied.The Brillouin-Raman fiber laser consists of a segment of 7 km long dispersion compensating fiber, 1455 nm Raman pump, tunable laser and double feedback loops.The BP wavelength must be closer to Raman peak gain to obtain more Stokes lines when RP is fixed at 250 mW.The power difference between the neighbouring Brillouin components and Rayleigh components was reduced by enhancing the BP power, the average intensity of Stokes lines was improved to the saturation value, simultaneously.Affected by the cross-gain in DCF, firstly the number of output lasing lines increase and then decrease when the BP power was adjusted from 1.8 dBm to 6.9 dBm.Maximum 37 output channels was obtained when BP power fixed at 4.4 dBm, the channel spacing is 0.078 nm.