为了严格分析入射光波长相对相位型菲涅尔透镜的设计波长发生漂移时对其聚焦特性的影响，采用时域有限差分方法作为严格的矢量分析工具，得到了相位型菲涅尔透镜的光焦度与入射光波长以及衍射效率与入射光波长的关系曲线。仿真结果表明：与标量理论结果类似，菲涅尔透镜光焦度随入射光波的增加总体呈线性上升趋势，衍射效率随入射光波长漂移时设计波长下降，且衍射效率低于标量理论分析结果。

In order to analyze the effect of the incident wavelength drift from the design wavelength of phase Fresnel lens on the focusing property of phase Fresnel lens,the dependent curves of focal power-wavelength and diffractive efficiency-wavelength for the phase Fresnel lens were obtained by adopting the finite-difference time-domain method (FDTD) as a rigorous vector analysis tool. The simulation results show that the focal power of a Fresnel lens increases with the wavelength,which is similar to the result of scale theory,the diffractive efficiency declines with the drifting of the incident wavelength,and it is lower than the analysis result of scale theory.