稀铋GaAs新型可饱和吸收体调Q/锁模的激光特性及微观机理研究

As a new generation of semiconductor materials, III-V compound with dilute bismuth attracted extensive attention around the world recently. By the incorporation of dilute bismuth into GaAs, the band gap of the semiconductor could be reduced significantly and the optical quality might have a great improvement. Due to these great properties, GaAs with dilute bismuth is expected to be a new generation of high performance semiconductor saturable absorber, thereby the investigations about the performance and mechanism are urgent to be carried on. . In this project, the characteristics of the Q-switched/mode-locked laser with dilute bismuth doped GaAs as a saturable absorber would be studied; PL spectrum and Z scan methods would be utilized to determine the band structure and the saturable absorption characteristics; first principle method will be performed to study the effect of the micro state and the components of the complex on the characteristics of the Q-switched/mode-locked laser. In addition, we plan to amend the laser rate equations, simulate the operation characteristics of dilute bismuth doped GaAs Q-switched /mode-locked laser and get the performance parameters optimized, for the purpose to reveal the key micro mechanism and the approach for the improvement of the performance. By combining the theoretical and experimental studies, more efficient atom design approach of dilute bismuth doped GaAs semiconductor saturable absorber would be explored, and a regular basic would be obtained which could provide guidance for designing a new type of semiconductor saturable absorber with higher power output and more stable performance. This project is not only being meaningful because of the obvious theoretical innovation, but also has high potential in actual application.

稀铋III-V族化合物作为新一代半导体功能材料近年来受到国际上广泛关注。将微量铋原子掺杂到GaAs晶体中可带来更大的带隙下降，并可大大改善GaAs晶体材料的光学质量，这些优良特性使其有望成为性能超优的新型半导体可饱和吸收体，相关性能和机理研究亟待开展。本项目拟研究稀铋GaAs作为可饱和吸收体的调Q/锁模激光特性；采用PL谱、Z扫描等方法研究Bi掺杂对GaAs能带结构及可饱和吸收特性的影响；采用第一性原理方法探讨掺杂方式和组份对其可饱和吸收特性及调Q/锁模性能的影响规律；修正激光器速率方程，仿真稀铋GaAs调Q/锁模激光器的运转特性，揭示性能优化的关键机制；通过理论计算和实验研究相结合，探索稀铋GaAs新型半导体可饱和吸收体的原子设计途径，为设计具有更高输出功率、性能更稳定的新型半导体可饱和吸收体提供理论依据和指导。本项目不仅具有突出的理论创新性，并且填补国内外空白，具有重要的应用前景。

通过本项目的实施，探明了稀铋GaAs中Bi杂质态的微观机理，以及Bi掺杂对其晶格常数、带隙、光学质量等宏观参数的影响；就其单光子吸收、双光子吸收、自由载流子吸收等多种吸收机制以及材料结构、掺杂和晶体缺陷对吸收特性的影响等得出了定量的结果；采用离子注入方法制备了Bi:GaAs材料，研究了不同离子注入条件制备的掺Bi:GaAs材料的可饱和吸收参数及其变化规律，以及不同掺Bi:GaAs材料作为可饱和吸收体，对其调Q/锁模激光特性的影响规律；采用速率方程理论优化稀铋GaAs调Q/锁模激光器的性能参数，得到其性能最佳情况下的关键性能参数，实验结果与理论结果相对照，探索新的性能最佳的稀铋GaAs新型半导体可饱和吸收体的原子设计方案。此外，我们还对碳纳米管、石墨烯、量子点材料、过渡金属硫化物、新型骨架纳米材料等低维纳米材料的非线性光学特性进行了理论和实验研究。