超短激光脉冲在多能级系统中的传输特性  

Propagation property of ultra-short laser pulses in multi-level quantum system

作　　者：陆剑清[1] 张向韵[2] 张诗按[1] 贾天卿[1] 孙真荣[1] 王祖赓[1] 

机构地区：[1]华东师范大学物理系,精密光谱科学与技术国家重点实验室,上海200062 [2]华东师范大学数学系,应用数学和交叉学科研究中心,上海200062

出　　处：《物理学报》2009年第12期8212-8216,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10574046);国家重点基础研究发展计划(批准号:2006CB806006;2006CB921105);教育部科技创新工程重大项目培育基金(批准号:30800);高等学校博士学科点专项科研基金(批准号:20050269011);上海市青年科技启明星跟踪计划(批准号:06QH14003);上海市研发基地应用协作能力建设专项基金(批准号:07dz22025)资助的课题~~

摘　　要：运用数值方法研究了超短激光脉冲在多能级系统中的传输特性.当激光脉冲能量相对较弱时,适当的脉冲面积可以实现自感应透明;激光脉冲能量逐渐增强,脉冲将产生分裂.脉冲分裂的基本面积(即脉冲实现稳定传播的最小面积)与二能级系统不同,而是A0=2π/κ,与激发态的能级个数和跃迁偶极矩密切相关.由于分裂和吸收,超短激光脉冲传输了一段距离以后,将演化为一个脉冲宽度更窄、峰值强度更高且面积为A0的超短激光脉冲.The propagation property of an ultrashort pulse in multi-level quantum system has been investigated with numerical method. A strong absorption is observed and its degree depends on the characteristic time of quantum system. For rather weak laser field,the self-induced transparency can still be observed with proper pulse area of the input ultrashort laser. When the ultrashort laser pulse becomes stronger,it will be split,and its basic split unit（i.e. the minimum area of a stably propagating laser pulse） A0 is not the same as that of two-level quantum system,which depends on the number of the excited states and their dipoles. Furthermore,after a rather long propagating distance,there only remains a shorter but more intense sub-pulse with an area of A0.

关 键 词：超短激光脉冲 多能级系统 特征时间 

分 类 号：O562.4[理学—原子与分子物理]