基于多层二硫化钨的可见光波段高效可饱和吸收体研究

二维材料具有宽带非线性光学响应和超快可饱和吸收特性，在脉冲激光调制方面展现出独特的优势，被广泛用于锁模器件中。但目前二维材料在可见光波段光调制器件的应用仍然面临巨大挑战，主要难点是二维材料难以同时兼备可见光波段低吸收损耗、高激光损伤阈值和优异环境稳定性。针对上述难点，基于申请人前期关于调控层间耦合作用对多层二硫化钨吸收效率显著改善的研究工作，本项目拟开发具有高可见光吸收效率和长使用寿命的多层二硫化钨可饱和吸收体。主要内容包括制备高质量二硫化钨与氧化铈薄膜形成的超晶格结构和探索氧化铈插层对多层二硫化钨可饱和吸收特性、抗激光损伤阈值以及环境稳定性的改善，从而实现优异可饱和吸收性能以及稳定被动锁模。本项目将为适用于可见光波段的低吸收损耗、长使用寿命的可饱和吸收体器件的设计和研制提供科学依据。

Two-dimensional materials have shown unique advantages in pulsed laser modulation and have been widely used in mode-locking devices due to their broadband nonlinear optical response and ultrafast saturable absorption characteristics. However, it is still a challenging task to achieve optical modulator applications in the visible spectral region based on two-dimensional materials and the main difficulty is to combine the low absorption loss of visible light, high laser-induced damage thresholds and excellent environmental stability. In view of the above difficulties, based on the significantly enhanced absorption efficiency in multi-layer tungsten disulfide with tuned interlayer coupling in my preliminary results, this project intends to develop the saturable absorber based on multi-layer tungsten disulfide with high absorption efficiency of visible light and long service life. The superlattice structure composed of high-quality tungsten disulfide and cerium oxide will be fabricated and the improvement of the saturable absorption characteristics, laser-induced damage threshold, and environmental stability of multi-layer tungsten disulfide by the intercalation method with cerium oxide will be explored to achieve excellent saturable absorption characteristics and stable passively mode-locking. This project will provide scientific basis for the design and development of saturable absorber devices suitable for visible region with low absorption loss and long service life.