Chen Ruishan, Wang Jinghao, Zhang Xiaoqiang, Wang Anting, Ming Hai, Li Feng, Chung Dick, Zhan Qiwen
Opt Lett. 2018 Feb 15;43(4):755-758. doi: 10.1364/OL.43.000755.
We demonstrate a novel all-fiber laser generating cylindrical vector beams with high slope efficiency and low threshold by introducing a long-period fiber grating into the laser cavity. Highly efficient mode conversion is realized by an LPFG at ∼1548 nm. Mode selection and spectrum filtering are achieved in combination with a two-mode fiber Bragg grating (TM-FBG). The fiber laser operates at a single wavelength of 1547.95 nm with a 30 dB linewidth of less than 0.18 nm and a side-mode suppression ratio (SMSR) of more than 56 dB. The lasing threshold and slope efficiency of the laser are 24.5 mW and 35.41%, respectively. The output power is 72 mW with an absorbed pump power of 225 mW. The variation of slope efficiency with respect to the reflectivity of the TM-FBG is investigated. Through adjusting the intra-cavity polarization controller, high-purity radially and azimuthally polarized beams are both obtained.
我们展示了一种新型全光纤激光器，通过在激光腔内引入长周期光纤光栅，可产生具有高斜率效率和低阈值的圆柱矢量光束。在约1548 nm处，由长周期光纤光栅实现了高效模式转换。通过结合双模光纤布拉格光栅（TM-FBG）实现模式选择和光谱滤波。该光纤激光器在1547.95 nm的单波长下工作，30 dB线宽小于0.18 nm，边模抑制比（SMSR）大于56 dB。激光器的激射阈值和斜率效率分别为24.5 mW和35.41%。吸收泵浦功率为225 mW时，输出功率为72 mW。研究了斜率效率相对于TM-FBG反射率的变化。通过调整腔内偏振控制器，获得了高纯度的径向和角向偏振光束。
