采用F-P光纤环滤波器的窄线宽环形腔光纤激光器

提出了一种采用F-P光纤环滤波器的窄线宽环形腔激光器，该激光器采用环形腔结构，两个耦合比为30:70的耦合器和一段2 m长的未泵浦掺铒光纤构成F-P光纤环滤波器，F-P光纤环滤波器产生的梳状谱，可以增大激光模式之间的自由光谱范围（FSR），在一定程度上减小跳模现象的发生，有利于模式的稳定。研究表明，通过对掺铒光纤的优化和耦合器的选择可以提高F-P光纤环滤波器的精细度，而F-P光纤环中的未泵浦掺铒光纤起到饱和吸收体的作用，使输出激光的线宽得到有效压缩。将保偏光纤光栅和F-P光纤环滤波器共同应用于环形腔掺铒光纤激光器，在室温下得到了3 dB线宽均小于0.07 nm（实验室光谱仪最小分辨率）的窄线宽双波长输出。在2 h的观测时间内，最大峰值功率波动小于0.4 dB，具有良好的稳定性。

Narrow linewidth ring cavity fiber laser using F-P fiber ring filter

A kind of narrow line-width fiber laser using F-P fiber ring filter was proposed and experimentally demonstrated, which has a ring cavity. A F-P fiber ring filter consisted of two optical couplers of 30:70 and a length of 2 m unpumped Erbium-doped fiber. The comb spectrum produced by F-P fiber ring filter can magnify the free spectral range of the laser mode, eliminate mode hopping and increase the stability of the mode in a certain extent. The research shows that the fineness of F-P fiber filter can be improved through the optimization of Erbium-doped fiber and the selection of couplers. Unpumped Erbium-doped in the F-P fiber ring acts as saturated absorber, which can compress the linewidth of output laser effectively. Polarization-maintaining fiber grating(PM-FBG) and F-P fiber ring filter are both applied into Erbium-doped laser, the output of narrow linewidth and dual-wavelength laser is obtained, and the 3 dB linewidth of dual-wavelength laser are both less than 0.07 nm(spectrometer minimum resolution). The fiber laser had a stable output whose maximal peak power fluctuation was less than 0.4 dB within observation time of 2 h.