中文摘要：

研究多普勒系统中的位相共轭三光子共振六波混频（SWM）．得到当入射激光为窄带线宽时，SWM频谱是消多普勒的，因此可成为一种研究原子或分子高激发态和高角动量态的高分辨相干非线性光谱学．本方法还具有位相匹配条件不严格，有良好的空间分辨率，光路配置简单等优点．

英文摘要：

We study the three-photon resonant six-wave mixing （SWM） with phase-conjugation geometry in Doppler system. The theoretical calculation indicates that the signal spectrum is Doppler-free when the laser line width is narrow. This technique provides a new spectroscopic tool for studying the highly excited atomic or molecular states with high resolution. It has advantages of uncritical phase matching condition, excellent spatial signal resolution and simple optical alignment.