基于Sagnac环和M-Z级联的可调谐掺铒光纤激光器

A tunable erbium-doped fiber laser based on cascaded filtering of Sagnac loop and M-Z filter

提出了一种基于Sagnac环和M-Z级联滤波的可调谐掺铒光纤(EDF)激光器,实验测得M-Z滤波器的梳状谱周期为2.2nm。将一段长为10m的保偏光纤(PMF)作为Sagnac环滤波器中的高双折射光纤,并测得其梳状谱周期为0.42nm。谐振腔中加入一段15km长的单模光纤(SMF),用来产生非线性效应,稳定激光输出。实验获得的单、双波长的激光线宽均小于0.07nm,峰值功率大于-17dBm,边模抑制比(SMSR)大于32dB,单、双波长激光的输出功率最大波动均小于1.2dBm。对加在M-Z上的驱动电压与Sagnac环中的偏振控制器(PC)进行调节,实现了各波长激光在2.2nm范围内整体连续可调谐。

A tunable erbium-doped fiber laser based on cascaded filtering of Sagnac loop and Mach-ZE- HNDER （M-Z） filter is proposed in this paper. In the experiment,the measured period of comb spectra of M-Z filter is 2.2 nm. A segment of 10 m long polarization-maintaining fiber （PMF） is used as the high birefringence fiber in Sagnan loop, and the measured period of comb spectra is 0. 42 nm. A segment of 15 km long single-mode fiber （SMF） is added to the resonator to generate nonlinear effect and stabi- lize laser output. The experimental results suggest that not only the linewidth of single wavelength laser is less than 0.07 nm,but also the linewidth of double-wavelength laser is less than 0. 07 nm. The peak powers of both the single wavelength laser and the double-wavelength laser are more than --17 dBm, and the side-mode suppression ratios （SMSRs） of both are more than 32 dB. The maximum output power fluctuations of the single wavelength laser and the double-wavelength laser are both less than 1.2 dBm. By adjusting the driving voltage of M-Z filter and changing the polarization state of polarization controller （PC） in Sagnac loop at the same time,the wavelengths of single wavelength laser and double wavelength laser can be continuously tuned within the range of 2.2 nm.