基于级联型光纤的孤子自频移增强特性

Characteristics of Enhanced SSFS Based on Cascaded Fiber

设计了一种10m掺铥光纤级联于3m大模场光子晶体光纤末端的结构,利用400fs、1 550nm脉冲光产生孤子自频移,在入射光功率相同的情况下,掺铥光纤末端的孤子频移量比大模场光纤末端多100~150nm,平均多30%左右.孤子与泵浦光在掺铥光纤末端的输出光谱表明,残留泵浦光作用于Tm3+,在1.8~2.1μm范围产生受激辐射,从而增强了拉曼效应,导致孤子自频移增强.实验结果揭示了一种增强孤子自频移效应的方法,对于了解孤子在光纤中频移特性和提高基于孤子自频移的可调谐光源的调谐范围等具有参考意义.

A structure was designed that a 10m thulium-doped fiber is cascaded to 3m large-modearea photonic crystal fiber,and soliton self-frequency shift was generated by a 400 fs,1 550 nm light pulse.At the same incident power,solitons in thulium-doped fiber experience more frequency-shift than that in large-mode-area fiber by 100-150nm（30% on the average）.Output spectra of soliton and pump at the end of thulium-doped fiber show that the stimulated radiation from Tm3＋ is generated among 1.8-2.1μm by residual pump,which results in greater Raman effect and cause the soliton selffrequency shift enhanced.The findings reveal a way to enhance soliton self-frequency shift,and have significance on extension of tunable range of laser based on soliton self-frequency shift.