分析了计算四波混频效率的表到式在考虑非线性相位失配因子和不考虑非线性相位失配因子两种情况下，四波混频效率计算的差别-Analysing the expression of DFWM in the optical fiber under the consideration of nonlinear phase mismatch factor, then comparing the result to the expression which includes only linear phase m