基于双光纤布拉格光栅的抽运激光器波长锁定器

运用耦合模理论推导了双光纤布拉格光栅(FBG)的透射率和反射率的解析表达式,进一步推导出带双光纤布拉格光栅激光器的增益方程。利用相关表达式讨论双光纤布拉格光栅的反射特性与透射特性,并探究对激光器增益曲线的影响。双光纤布拉格光栅由结构和特性相同的单光纤布拉格光栅构成,通过优化两光纤布拉格光栅之间的距离得到最佳的锁模特性。在工作温度为0℃,20℃,70℃时,分别测量了带双光纤布拉格光栅和单光纤布拉格光栅波长锁定器的非致冷抽运激光器的输出光谱。其结果表明带双光纤布拉格光栅的非致冷抽运激光器输出光谱的稳定性得到了显著改善。在0~70℃温度范围内能稳定工作,波长漂移为0.2 nm,边模抑制比达45 dB,半峰值宽度小于1.57 nm。

Wavelength Locker of Pump Laser Based on Dual Fiber Bragg Grating

The analytical expression of transmissivity and reflectivity of dual fiber Bragg grating (FBG) has been given based on the mode coupled theory, and the gain equations of the pump laser with dual FBG are also obtained. The characteristics of reflection and transmission for dual FBG were analyzed by relevant expression, and the effects of laser gain curve were studied. The dual FBG is composed of a pair of FBGs with the same structure and properties. The spacing of the two FBGs has been optimized to get the best mode-locking characteristics. The output spectral characteristics of the uncooled pump laser with dual FBG or single FBG wavelength locker are practically measured when the operating temperature are 0 ℃, 20 ℃, 70 ℃, respectively. The results show that the output spectral characteristics of the uncooled pump laser with dual FBG have been greatly improved. The uncooled pump laser can work steadily in the temperature range from 0 to 70 ℃. The wavelength shift is 0.2 nm. The side mode suppression ratio is more than 45 dB, and the spectral band width is less than 1.57 nm.