折-衍混合长焦深光学元件的焦深特性  

Focal depth characteristics of hybrid refractive-diffractive optical element with long focal depth

作　　者：张慧[1] 丁雪梅[1] 谭久彬[1] 

机构地区：[1]哈尔滨工业大学超精密光电仪器工程研究所,黑龙江哈尔滨150001

出　　处：《光学精密工程》2008年第1期64-70,共7页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.50675052)

摘　　要：分析了基于能量守恒法获得的对数光锥位相函数的特点,建立了长焦深元件焦深与系统f/#及衍射元件浮雕深度间的函数关系,基于菲涅耳衍射公式分析了参数不同时元件的轴向光强分布规律。仿真结果表明:在给定波长及焦距的条件下,折-衍混合长焦深元件相对同f/#的球面折射透镜的焦深扩展倍数取决于衍射元件的浮雕深度,其值越大,焦深扩展倍数越大,焦深内轴向光强分布越接近平顶分布;焦深一定时,小f/#系统更易获得焦深内轴向光强的平顶分布。The logarithmic phase function based on uniform-intensity principle was analyzed, and the functional relationship among the focal depth of a long focal depth element, the optical f/# and the profile depth of a diffractive element was set up in terms of logarithmic phase function. The simulation of on-axis intensity distribution of the element was analyzed based on Fresnel diffraction formula with different parameters. Simulation results indicate that, when the focal length and wavelength are given, the factor in focal depth compared with the same f/# spherical refractive lens is determined by profile depth of diffractive element; when the profile depth is increased, the factor is larger and the on-axis intensity distribution in focal depth offers great uniform characters. For an unchanged focal depth value, when the optical f/# is decreased, the uniform character of on-axis intensity distribution in focal depth is better.

关 键 词：焦深 折-衍混合光学元件 长焦深元件 

分 类 号：TH703[机械工程—仪器科学与技术]