中文摘要：

波前编码景深延拓技术是在非相干光学系统的出瞳处加入三次位相板,对成像进行解码处理而获得清晰图像以扩大光学系统景深的技术.文章通过深入研究波前编码光学成像系统的调制传递函数（MTF）,分析离焦量和位相板的调制系数对MTF的影响,并通过数值计算和曲线拟合得到位相板调制系数、系统带宽、景深延拓性能之间的关系.该研究成果为位相板的调制系数的选择和景深延拓光学系统的设计提供依据.

英文摘要：

The wavefront coding extension of the depth of field （DOE） for an imaging system is achieved by inserting a third order phase plate into the pupil plane of a spatially incoherent imaging system.The encoded image can be digitally restored to produce a final image with improved depth-dependent details.The characteristics of the system are studied,and the modulation transfer function （MTF） varying with defocus and modulation coefficient,α,of the third order phase mask is analyzed,the results about the effects of α value on the extension of DOE and the bandwidth are obtained.The results are conducible to the design of wavefront coding optical system and the choice of an appropriate α velue.