Abstract The nonlinear absorption and ultrafast dynamics process of WS2 and WS2-Ag nanocomposite were investigated by using nanosecond Z-scan measurements and femtosecond time-resolved transient absorption spectrum, respectively. Z-scan measurements showed that WS2 exhibit saturation absorption (SA) at low excitation intensities, with the increase of incident intensity, a switch from SA to reverse saturation absorption (RSA) occurs, but WS2-Ag nanocomposite exhibit SA at the same intensity. Transient absorption spectrum provided information show that the response time did not change much. The investigation shows that WS2 and WS2-Ag nanocomposite can be used for mode-locker and optical switcher.

中文翻译：

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Ag纳米粒子对WS2的增强非线性光学吸收

摘要 分别采用纳秒Z扫描测量和飞秒时间分辨瞬态吸收光谱研究了WS2和WS2-Ag纳米复合材料的非线性吸收和超快动力学过程。Z 扫描测量表明 WS2 在低激发强度下表现出饱和吸收 (SA)，随着入射强度的增加，发生从 SA 到反向饱和吸收 (RSA) 的转换，但 WS2-Ag 纳米复合材料在相同强度下表现出 SA。瞬态吸收光谱提供的信息表明响应时间没有太大变化。研究表明，WS2和WS2-Ag纳米复合材料可用于锁模器和光开关器。