设计了一种单激光器双光子三维光存储系统。区别于目前普遍采用的双激光器方案, 单激光器双光子三维光存储系统结构紧凑、体积小、光程短、所需元器件少。通过衍射光学元件的使用, 实现了单一激光器, 单一物镜和单一主光路的目标。该系统的聚焦伺服线性区为4λ, 与现有的DVD伺服系统兼容。系统选层距离与衍射光学元件的位移距离呈近似的线性关系, 选层伺服易于控制。当选层厚度为0.3mm时, 衍射光学元件的最大位移距离为5.254mm, 系统所需空间小。衍射光学元件表面微结构的最小环带间距为18.202μm, 高度为1.6μm。

Introduced is a compact optical system for two-photon three-dimensional optical data storage with a single femtosecond laser. Compared to traditional designs, by using a diffractive optical element (DOE) in the system, one single laser and one objective lens in a single optical path for servo beam is achieved. The optical system owns a linear region of 4λ which is compatible with current DVD servo module. The DOE is designed to control the layer-selection process conveniently, as there is a linear correlation between the displacement of DOE and that of the layer-selection. When the layer-selection thickness is 0.3mm, the maximum displacement of DOE is 5.254mm. The minimum grating period and the depth of DOE is 18.202μm and 1.6μm, respectively.