【摘要】 考虑 L orentz局域场效应的影响 ,我们在 L iouville运动方程的基础上用微扰理论分析了一个三能级系统的非线性响应 .在非线性光学响应中 ,两波矢分别为 k1 ,k2 的连续相干脉冲将会在新的方向产生新的光波 .计算之后 ,我们给出四波混频信号关于 L orentz局域场因子 l的表达式 ,发现负时间延迟时在 2 k2 - k1 方向仍有四波混频信号 ,四波混频信号的频率也有所改变更多还原

【Abstract】 Using a perturbation theory based on the Liouville equation of motion,we analyze the nonlinear response of a three-level model system,after considering the Lorentz local field effect.In the nonlinear optical response,two consecutive coherent pulses with the wave vector k₁ and k₂ generate new light waves in the new directions.The expression for the four-wave mixing signal,a third response,is given by accounting of the Lorentz local field.It is found that an four-wave mixing signal still persists in the direction 2k₂-k₁ for the negative time delay,and the frequency of the four-wave mixing signal has a shift related to the Lorentz local field factor l.更多还原