用三区三元相位滤波器提高近场光存储系统的焦深

为了提高近场固体浸没透镜光存储系统的焦深,设计了三区三元相位滤波器.设计建立在矢量衍射理论基础上,应用MATLAB优化工具箱优化设计出可以获得最大焦深的滤波器结构参数.在设计过程中,我们限定记录光斑的大小与没有滤波器时的光斑大小相等,而光斑的强度减小一半,所设计的滤波器可以使近场固体浸没透镜光存储系统的焦深提高1.6倍...

Increasing focal depth of near-field optical storage systems by a three-zone ternary phase filter

Based on the vector diffraction theory and by using the optimizing toolbox in MATLAB,a three-zone ternary phase filter is designed to increase the focal depth of a near-field solid immersion lens optical storage system.In the process of design,the spot intensity is constrained to half of the spot intensity without a filter and the spot size is constrained to equal to the spot size without a filter.When the designed filter is applied a SIL near-field optical storage system,it can improve the focal depth by 1.6 times.At the same times,compared with an optimally designed three-zone binary filter,the focal depth also increased obviously on the condition of identical spot size and intensity.These results are useful to near-field high-density optical storage.