Yang H, Zhang J, Zhang J, Zhao L Z, Li Y J, Teng H, Li Y T, Wang Z H, Chen Z L, Wei Z Y, Ma J X, Yu W, Sheng Z M
Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Jan;67(1 Pt 2):015401. doi: 10.1103/PhysRevE.67.015401. Epub 2003 Jan 16.
Strong third-order harmonic (TH) emission is observed with a conversion efficiency higher than 10(-3) from a plasma channel formed by self-guided femtosecond laser pulses propagating in air. The main characteristics of TH emission in various conditions and the phase-matching condition between the fundamental and the TH wave are investigated. An optimized condition is found, under which the TH conversion efficiency is maximized. Our experimental results show that radiation of the emission in ultraviolet wavelength range makes a major attribution to TH emission, whereas the effects of self-phase modulation are not important when intense laser pulses interact with gaseous media.
在空气中由自引导飞秒激光脉冲形成的等离子体通道中，观察到了强三阶谐波（TH）发射，其转换效率高于10^(-3)。研究了各种条件下TH发射的主要特性以及基波与TH波之间的相位匹配条件。找到了一个优化条件，在此条件下TH转换效率最大化。我们的实验结果表明，紫外波长范围内的发射辐射对TH发射起主要作用，而当强激光脉冲与气态介质相互作用时，自相位调制的影响并不重要。
