光子学报, 2011, 40 (1): 24, 网络出版: 2011-03-08
少周期脉冲激光在稠密的Λ型三能级原子介质中传播时的频谱分析
Spectrum Analysis of a Few-cycle Laser Pulse Propagating in a Dense Λ-type Three-level Atomic Medium
摘要
利用由预估校正法和时域有限差分法求解全波Maxwell—Bloch方程得到的数值解,研究了超短脉冲激光在稠密的三能级原子系统中的频谱演化规律.研究发现:不管是在稀疏介质中还是在稠密介质中,由于自相位调制作用,频谱均被展宽,而在稠密介质中频谱的宽度要远大于稀疏介质中的情况,这主要是由于近偶极—偶极作用导致的.在稠密介质中,由于近偶极—偶极作用和自相位调制作用,频谱出现高频连续波,可以得到覆盖频率范围为10 ωp的超连续谱.
Abstract
Full Maxwell-Bloch equations were solved by Predictor-Corrector method and finite- difference time-domain method to investigate spectrum of a sub-cycle laser pulse propagating in a dense Λ-type three-level atomic medium.It is found that both in a dilute medium and a dense medium,the spectrum is broaden due to the self-phase modulation(SPM); however,the width is much larger in the dense medium than that in a dilute medium because of NDD interaction.In the dense medium,the supercontinuum spectrum occurs due to SPM and NDD interaction,and the maximum frequency is 10 ωp.
马慧, 宋强. 少周期脉冲激光在稠密的Λ型三能级原子介质中传播时的频谱分析[J]. 光子学报, 2011, 40(1): 24. MA Hui, SONG Qiang. Spectrum Analysis of a Few-cycle Laser Pulse Propagating in a Dense Λ-type Three-level Atomic Medium[J]. ACTA PHOTONICA SINICA, 2011, 40(1): 24.