大脉冲能量单层CVD石墨烯被动调Q掺镱双包层光纤激光器

Large Pulse Energy Passively Q-switched Yb^(3+) Doped Double Clad Fiber Laser with Mono-layer CVD Graphene

基于单层化学气相沉积(CVD)石墨烯可饱和吸收体的大脉冲能量被动调Q双包层光纤激光器.采用三明治结构,将CVD法生长的单层石墨烯通过聚甲基丙烯酸甲酯(PMMA)从铜箔上转移到光纤端面,制备成PMMA/石墨烯调Q器.采用全光纤线性腔结构,掺镱双包层光纤和PMMA/单层石墨烯分别作为增益介质和被动调Q器件,大功率975nm半导体激光器作为泵浦源,大比例(95%)功率耦合输出,成功实现了中心波长为1 063.6nm大脉冲能量的稳定调Q光纤激光器.调Q脉冲序列重复频率在9.7~26.46kHz连续可调,当泵浦功率为756.1mW时,最大输出功率为46mW,最小脉宽为4.5μs,并且获得的最大单脉冲能量为1.7μJ.实验结果表明,单层CVD石墨烯性能优异,将有望在双包层光纤激光器中实现更大平均功率、单脉冲能量的激光输出.

A large pulse energy passively Q-switched Yb3＋ doped double clad fiber laser with mono-layer chemical vapor deposition （CVD） graphene is reported. The mono-layer CVD graphene was transferred from copper to the fiber end with poly methyl methac rylate （PMMA）,and then prepared to Q-switcher with sandwich structure. On the basis of ring resonant cavity, Yb3＋ doped double clad fiber pumped by high power 975 nm semiconductor laser and PMMA/mono-layer graphene served as gain medium and passively Q-switcher respectively. Stable passively Q-switched fiber laser centered at 1 063.6 nm with large single pulse energy has been a- chieved successfully. The repetition rate is tunable from 9.7 kHz to 26.46 kHz along with the increase of the incident pump power. The maximum output power and the minimum pulse duration is 46 mW and 4.5 μs respectively when the incident pump power is 756. 1 mW. In addition,the maximum single pulse energy of 1.7 μJ is also obtained. This achievement is,to the best of our knowledge,the largest pulse energy among all-fiber graphene Q-switched lasers. Experimental results show that great average power and pulse energy double clad fiber laser can be achieved with high quality mono-layer CVD graphene as Q-switcher.