基于二维纳米材料可饱和吸收体的中红外波段超短脉冲掺铒波导激光器

Ulrtashort pulse lasers in mid-infrared region have many important applications in the fields of spectroscopy, remote sensing, ladar, medical treatment, fine processing, gas detection, environmental monitoring, and military defense. Waveguide has advantages such as high gain, low threshold and easy integration. However, research on waveguide lasers, especially on ultrashort pulse waveguide laser operating at mid-infrared region, is far less researched. On the other hand, novel 2-D nano-materials like topological insulator Bi2Se3 and MoS2 acting as saturable absorber have been theoretically predicted to be saturated in broad band. However, at present, research on these saturable absorbers has been very limited mainly in the near infrared region. There is no any report regarding the ultrashort pulse laser in mid-infrared based on these 2-D nano-materials saturable absorbers. Therefore, this project integrates the research of 2-D nano-materials saturable absorbers with Er-doped waveguide laser to develop more superior 2-D nano-materials Q switcher or Mode locker with big modulation depth, low insertion loss, and high damage threshold. Moreover, theoretical research, numerical simulation, optimization and experimental study on 2-D nano-materials based Q-switched and Mode-locked Er-doped ultrashort pulse waveguide laser will be carried out. The final purpose of this project is to obtain high-performance Q-switched and mode-locked waveguide lasers operating at about 3.0 micron. The project is advantageous to better understanding of optoelectronic property of 2-D nano-materials and is also helpful for the development and application of Er-doped ultrafast waveguide lasers.

光谱学、遥感、医疗、工业精密加工，气体检测、环境监测和军事国防等诸多领域都需要高能量的中红外波段激光光源。波导具有高增益、低阈值、易集成等优点，但对波导激光器的研究，尤其是对中红外波段超短脉冲波导激光器的研究还很薄弱。新型二维纳米材料拓扑绝缘体Bi2Se3和MoS2具有宽带可饱和吸收特性，然而目前对于这些材料的研究局限在近红外波段，尚无基于这些可饱和吸收体在中红外波段获得超短脉冲激光的报道。本项目新型二维纳米光电材料可饱和吸收体与掺Er3+波导结合起来研究，研制调制深度大、插入损耗低、损伤阈值高的新型调Q和锁模器，并开展这些新型可饱和吸收体调Q和锁模掺Er3+波导激光器的理论分析、数值模拟、优化设计、实验研究和可饱和吸收特性的比较研究，以期获得3.0μm中红外波段超短脉冲波导激光器。本项目研究有助于深化对新型二维纳米材料光电特性的认识，有助于促进掺Er3+超快波导激光器的开发应用。

近红外（超短）脉冲激光发展的已经比较成熟，中红外波段（超短）脉冲激光的发展相对滞后。然而，在光谱学、遥感、医疗、气体检测、环境监测和军事等诸多领域都需要高强度的中红外波段激光光源。另一方面，调Q和锁模是产生（超短）脉冲激光的主要技术手段。当前制约中红外（超短）脉冲激光发展的一个重要因素是缺乏可靠高效的可饱和吸收体。二维纳米材料的宽带可饱和吸收特性吸收了越来越广泛的研究兴趣，这类吸收体的研究主要在近红外波段。本项目主要研究二维纳米材料的可饱和吸收特性，并将其应用到调Q/锁模掺Er3+中红外激光中，力求在掺Er3+波导脉冲激光研究中取得突破。本项目组主要完成了如下研究工作：（1）深入研究了石墨烯、过渡金属硫化物、拓扑绝缘体、量子点和二维烯等材料，通过反复表征测量材料的特征参数，优化制备了高性能的纳米材料吸收体；与激光镀膜技术相结合，研制了各种波段的可饱和吸收镜；（2）将这些可饱和吸收镜应用到Pr3+、Nd3+、Tm3+和Er3+固体激光中，实现了可见光、1-2微米近红外、2.7微米中红外脉冲固体激光；（3）利用Fe:ZnSe晶体作为饱和吸收体，实现了Er3+中红外调Q激光国际上最短的脉冲宽度，以及首个波长可调谐的Er3+中红外脉冲激光；（4）用钛蓝宝石飞秒激光放大器，在Er3+陶瓷材料中写入信道波导，与二维烯可饱和吸收镜结合，在国际上首次实现了中红外Er3+波导脉冲激光。.在本项目资助下，我们已发表相关SCI论文16篇（其中第一和通讯作者SCI论文11篇），另有多篇论文在投稿和撰写中。培养博士生2名，硕士生5名。