【作者】 邢昕； 袁伟； 李泽汉； 薛冰； 小林孝嘉； 杜鹃； 赵元安； 冷雨欣； 邵建达；

【Author】 Xin Xing;Wei Yuan;Zehan Li;Bing Xue;Takayoshi Kobayashi;Juan Du;Yuanan Zhao;Yuxin Leng;Jianda Shao;State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences;University of Chinese Academy of Sciences;Key Laboratory of Materials for High Power Laser,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences;Advanced Ultrafast Laser Research Center,University of Electro-Communications;

【机构】 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室； 中国科学院大学； 中国科学院上海光学精密机械研究所中科院强激光材料重点实验室； 日本电气通信大学先端超高速激光研究中心；

【摘要】 利用泵浦探测技术,采用中心波长为800nm,重复频率1kHz的飞秒激光脉冲,对Nb₂O₅/SiO₂啁啾镜介质膜的内部与飞秒激光损伤相关的超快动力学进行了研究。发现强的泵浦光脉冲辐照结束后飞秒乃至几十皮秒的范围内,啁啾镜对探测光的反射率有一定程度的下降。分析得知,反射率降低的主要原因是泵浦光在介质膜的Nb₂O₅层内激发的大量的自由电子对探测光吸收所致,且该过程对激光诱导损伤过程起主导作用。通过反射率的变化,对其介质膜内导带电子弛豫过程进行探究,计算了其衰减寿命,并给予了相应的解释。更多还原

【Abstract】 Ultrafast carrier dynamics in Nb₂O₅/SiO₂ chirped mirrors excited by 800 nm,1 kHz femtosecond laser had been investigated by pump-probe technique.Reflectance of dielectric chirped mirrors was found reduced after pump pulse excitation femtosecond and dozens of picosecond range.The reduction is mainly ascribed to the absorption of conduction electrons inside the Nb₂O₅ layers in dielectric chirped mirror film,which play important role in laser induced damage.To investigate the ultrafast dynamics in dielectric film in detail,the relaxation lifetime of electrons in the conduction band has been calculated and interpreted.更多还原