超短激光脉冲在共振介质中传播的时空特性

Spatial and temporal characteristics of ultrashort laser pulses propagation in resonance media

用有限差分方法求解Maxwell和Bloch的联立方程,计算得到共振介质中超短光传播的时空特性。结果表明,在考虑空间效应时,峰面积为2π的超短光脉冲不再以孤子的形式传播,光场的形状将发生变化,变形的程度和光与物质相互作用的强度有关强度较小时,光场包络在时间和空间两方面都展宽;强度较大时,则发生分裂。光与物质相互作用的强度与光场大小、光场频率、偶极矩、失谐以及共振粒子浓度等因素有关。

Laser propagating through resonance media taking into account of spatial effect was discussed by simultaneously solving the Maxwell-Bloch equations with definite differential method. Results indicate that the propagation of a 2π pulse form would no longer be a soliton, its profile would expand, and the degree of distortion depends on the interaction intensity of laser and material: stronger interaction causes more distortion till the profile split. The interaction intensity was decided by such elements as the laser frequency, laser intensity, the dipole of material, detuning and the concentration of resonance particles.