采用准分子激光器成功地在低掺杂普通铒纤上制作出5 cm的光纤光栅分布反馈布拉格(DFB)激光器,铒纤的峰值吸收率为5 dB/m,在100 mW,980 nm抽运光条件下,光纤激光器的输出功率为50 μW,边模抑制比为50 dB。使用耦合模理论分析了一段5 cm带相移的分布反馈布拉格光纤激光器输出光强同腔内损耗及相移量的关系,计算结果表明,光纤腔内的损耗对激光器的输出具有非常重要的影响,大的损耗对应获得最大功率的光栅耦合强度相应减小,因此,在低掺杂铒纤上制作分布反馈布拉格激光器必须正确估计光纤激光器的腔内损耗,选择合适的光栅耦合强度,可以获得较大的输出功率。

A 5 cm fiber Bragg grating distributed feedback Bragg (DFB) fiber laser is fabricated by using 248 nm KrF excimer laser, the fiber used is regular Er-doped fiber with peak absorption of 5 dB/m, the fiber laser has a output power of 50 μW and 50 dB sidelobe suppression ratio by a 100 mW 980 nm pump laser. Coupled-mode theory was introduced to analyze DFB fiber laser output characteristics and transfer-matrix method was used to simulate a 5 cm phase shifted DFB fiber laser. From the analysis, it showed that the cavity loss is a very important factor affecting the output power, larger loss corresponds to lower grating coupling coefficient. Hence, when fabricating DFB fiber laser on regular Er-doped fiber, the cavity loss evaluation and coupling coefficient optimization could yield high output power.