Propagation of Intense Femtosecond Laser Pulses in Deuterated Methane and Deuterium Cluster Jets

• Published in: Plasma science & technology Vol. 13; no. 1; pp. 3 - 10
• Main Author: 周子理 刘建胜 卢海洋 鞠晶晶 王成 夏长权 王文涛 邓爱华 许毅 冷雨欣
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.02.2011
• Subjects: 光脉冲传输; 喷气机; 强激光脉冲; 电子密度分布; 飞秒激光脉冲
• ISSN: 1009-0630
• DOI: 10.1088/1009-0630/13/1/02

Propagation of intense femtosecond laser pulses （60 fs, 800 nm, 120 m J, 6 × 10^17 W/cm^2 in vacuum） in supersonic （CD4）N and （D2）N cluster jets at different backing pressures was studied. Pump-probe interferometry is employed to investigate the propagation of laser beams in dense cluster jets by examining the electron density distribution of plasma chan- nels. It was found that propagation effects, including ionization-induced defocusing and laser attenuation of incident pulses, are very different in the （CD4）N and （D2）N cluster jets. Different ionization states of CD4 and D2 molecules were observed by analyzing the transverse electron density profiles of the plasma channels and should be considered as a major reason for the differences in the propagation effects. Numerical simulations of the nonlinear propagation of femtosecond laser pulses in （CD4）N and （D2）N cluster jets were performed, and the results indicated a good reproduction of the experimental data.