稠密共振介质中近偶极-偶极相互作用的局域场效应

摘要

为研究存在由近偶极-偶极相互作用诱导的局域场效应时超短强激光脉冲与稠密共振介质相互作用的特性,采用光与物质相互作用的半经典理论,建立了稠密二能级体系中考虑原子间近偶极-偶极相互作用的修正光学Bloch方程,并用四阶Runge-Kutta法数值求解了该方程.研究结果表明:局域场效应对稠密二能级体系中Bloch矢量的瞬态相干过程和稳态性质都具有强烈的调制作用.并由此提出了调控稳态粒子数布居的两种方案.%The interactions between an ultrashort intense pulse and a dense resonant medium with local-field effects induced by near-dipole-dipole interaction were investigated. According to the semi-classical theory of light-matter interaction, the modified Bloch equations were established with near-dipole-dipole interactions in an optically dense two-level medium, and an accurate and efficient fourth-order Runge-Kutta method was applied for solving the equations. The numerical results show that, during the transient coherence, the evolutions of Bloch vectors and the final state of inversion are strongly modulated by the local-field effects. Furthermore, two modulation schemes of Bloch vectors in dense two-level media were proposed.