用于DVD光学头的三焦点单片物镜设计  

Design of three-focus single objective lens used in DVD pick-up head

作　　者：黄文浩[1] 雷双艳[1] 胡衍雷[1] 孟祥儒[1] 

机构地区：[1]中国科学技术大学精密机械与精密仪器系,安徽合肥230027

出　　处：《光学精密工程》2008年第10期1793-1799,共7页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.50335050);国家863高技术研究发展计划基金资助项目(No.2006AA042311)

摘　　要：为了兼容CD、DVD、HD-DVD 3种盘片,设计了适用于780、650、405 nm3个波长的二元衍射面和非球面相结合的单片物镜,3个波长对应的物镜数值孔径分别为0.45、0.60和0.65。介绍了单物镜实现三焦点原理;论述了二元衍射面和非球面的设计理论和结构参数,即二元衍射面刻环区域被分割成两个同心环形区域,根据谐衍射原理,每个区域对不同的波长设定不同的衍射级次;最后,根据光学头物镜的性能评价参数,应用ZEMAX软件进行理论模拟和公差分析。结果表明,所设计的物镜波像、波前均方差分别<0.07λ和0.035λ,空间截止频率>1 200 cycle/mm,曲率半径和厚度公差为300 nm,能满足实际应用的技术要求。In order to be compatible with CD, DVD and HD-DVD disc, a single objective lens with a binary diffractive surface and an aspherical surface was designed for three wavelengths of 780, 650 and 405 nm, and the numerical apertures are 0.45, 0.60 and 0.65, respectively. The working principle of the three-focus objective lens was presented. Then, the design theory of the aspheric objective lens and the parameters of the binary diffractive surface and aspherical surface were described in detail. The binary diffractive surface was divided into two concentric radial zones, each radial region set different diffraction orders for different wavelengths according to the harmonic diffraction theory. Finally, the ZEMAX was used in the theoretical simulation and tolerance analysis on the single objective lens based on the metewand of the aspheric objective lens. The simulation results show that OPD rms and wavefront rms are less than 0.07 λ and 0. 035 λ, respectively. Spacial cutoff frequency is greater than 1 200 cycle/ram, and the tolerance of radial curvature and the thickness tolerance are 300 nm, which can satisfy practical requirement.

关 键 词：光学头 三焦点物镜 ZEMAX软件 

分 类 号：TH703[机械工程—仪器科学与技术] TP333.4[机械工程—精密仪器及机械]