Xu Yingtian, Hu Hanfei, Wu Hongda, Xu Chongyang, Zhang He, Jin Liang, Zou Yonggang, Ma Xiaohui, Yin Jingzhi
State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China.
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qian-Jin Street, Changchun 130012, People's Republic of China.
ACS Appl Mater Interfaces. 2021 May 12;13(18):21748-21755. doi: 10.1021/acsami.1c02762. Epub 2021 Apr 29.
We demonstrate CuCrO (CCO) nanoparticle (NP)-polyimide (PI) composite film as a saturable absorber (SA) to regulate the output characteristics of passively Q-switched fiber laser at 1.55 μm. Based on the reverse saturable and saturable absorptions of the CCO NP-PI film, the passively Q-switched fiber laser expressed two stages with the increase of pump power for substantial performance enhancement. Reverse saturation absorption is observed to introduce appropriate cavity loss, which constructs effective pathways for promoting both the modulation depth and over threshold degree, as well as reducing the photon lifetime. In particular, our results realized the pulse duration and repetition rate compressing simultaneously for the first time. The second stage output laser exhibits a peak power of 1016 mW and a single pulse energy of 183 nJ, which are about 88 and 9 times higher than those of the first stage. Furthermore, the optical-optical conversion efficiency is up to 1270%. All of these can evidently demonstrate the importance of the appropriate cavity loss design for optimizing the Q-switched pulse laser output characteristics.
我们展示了CuCrO（CCO）纳米颗粒（NP）-聚酰亚胺（PI）复合薄膜作为一种可饱和吸收体（SA），用于调节1.55μm被动调Q光纤激光器的输出特性。基于CCO NP-PI薄膜的反饱和吸收和饱和吸收，随着泵浦功率的增加，被动调Q光纤激光器表现出两个阶段，以实现显著的性能提升。观察到反饱和吸收引入了适当的腔损耗，这为提高调制深度和过阈值程度以及缩短光子寿命构建了有效途径。特别是，我们的结果首次实现了脉冲持续时间和重复频率的同时压缩。第二阶段输出激光的峰值功率为1016 mW，单脉冲能量为183 nJ，分别比第一阶段高出约88倍和9倍。此外，光光转换效率高达1270%。所有这些都能明显证明适当的腔损耗设计对于优化调Q脉冲激光输出特性的重要性。
