石墨烯-Bi2Te3异质结锁模的全固态超快激光研究

Study on mode-locked lasers based on two dimensional layered saturable absorbers is becoming a new research focus in the field of laser technology. Recently, graphene-Bi2Te3 heterostructure was found to be a new saturable absorber which exhibits better saturable absorption behavior than graphene or Bi2Te3. Furthermore, both the photocarrier dynamics and nonlinear optical modulation of this heterostructure material are variable by tuning the coverage of Bi2Te3 on graphene that means graphene-Bi2Te3 heterostructure is conducive to generating high energy and ultrashort pulse. So that graphene-Bi2Te3 heterostructure is expected to play an important role in the field of mid-infrared ultrafast lasers as a promising novel saturable absorption material. This subject is focusing on researching the optical absorption properties of graphene-Bi2Te3 heterostructure systematically, further fabricating graphene-Bi2Te3 heterostructure saturable absorption mirrors, moreover, realizing all-solid-state mode-locked lasers at 1~2 μm in Nd3+, Yb3+ and Tm3+ doped laser crystals. This subject is promoting the basic research and application of graphene-Bi2Te3 heterostructure, in order to lay a theoretical and technical foundation for achieving 1~2 μm all-solid-state mode-locked lasers.

利用新型二维可饱和吸收体锁模来实现锁模激光输出是激光技术研究领域的热点之一。石墨烯-Bi2Te3异质结是一种新型可饱和吸收体，表现出比单纯石墨烯和Bi2Te3更优异的可饱和吸收性能。并且通过调节石墨烯上Bi2Te3的覆盖率可有效调节异质结材料的激子动力学和非线性光学性能，能够适应不同波段的高能量、短脉宽超快激光器的实际应用，因此在超快激光领域有巨大的应用潜力。本项目将系统研究石墨烯-Bi2Te3异质结的吸收性能；制备具有应用价值的石墨烯-Bi2Te3异质结可饱和吸收镜；基于掺稀土离子Nd3+、Yb3+和Tm3+的激光晶体，实现石墨烯-Bi2Te3异质结锁模的1~2μm全固态超快激光输出。通过该课题的研究，将加快石墨烯-Bi2Te3异质结这一新型锁模材料的基础研究，为提高1~2μm波段全固态超快激光性能奠定理论和实践基础。

石墨烯-Bi2Te3异质结作为一种新型宽带可饱和吸收体，在超快激光领域有较大的应用潜力。本项目采用自组装溶剂热法合成了石墨烯-Bi2Te3异质结，作为对比还合成了Bi2Te3和Sb2Te3纳米片，系统研究了各自的物理性能。利用旋涂方法制备了相应的可饱和吸收镜，测试发现石墨烯-Bi2Te3异质结表现出比纯Bi2Te3和Sb2Te3更优异的可饱和吸收性。进一步在Yb:GAB晶体中实现了~1.0μm石墨烯-Bi2Te3异质结调Q激光输出，基于Tm:YAP晶体实现了~2.0μm Sb2Te3调Q激光输出，基于Nd:YVO4晶体实现了石墨烯-Bi2Te3异质结调Q锁模激光输出。此外，我们还探索了其他基质晶体的生长及光学性能。上述研究成果将为基于其他二维可饱和吸收体的超快激光研究提供一定的实践指导。项目执行期间发表SCI论文4篇，待发表2篇，申请专利一项。