Diffractive super-resolution elements applied to near-field optical data storage with solid immersion lens
Diffractive super-resolution elements applied to near-field optical data storage with solid immersion lens
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DOI：
10.1088/1367-2630/6/1/075
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发表时间：
2004-07
影响因子：
3.3
通讯作者：
Yao-ju Zhang;Hua-ceng Xiao;Chong-wei Zheng
中科院分区：
文献类型：
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作者：
Yao-ju Zhang;Hua-ceng Xiao;Chong-wei Zheng
利用角谱理论，采用固体浸没透镜（SIL）和二元相位衍射超分辨率元件（DSE）的近场光学数据存储中的强度分布用单个定积分表示。针对低数值孔径 (NA) 系统和高数值孔径 (NA) 系统，对 SIL 系统的二元双区相位 DSE 的超分辨率进行了数值研究。低数值孔径系统的结果表明，优化二元双区相位 DSE 的区域边界和相位可以减小光斑尺寸。还讨论了斯特列尔比、旁瓣强度和轴向特征长度。此外，二元双区相位滤波器可以改变焦点位置，从 SIL-空气界面转移到空气，但光斑尺寸会增加。对于高数值孔径系统，传输场的 y 和 z 偏振分量随着 DSE 的边界和相位深度的增加而增加。当相界较小且相深接近π时，DSE的超分辨效果更加明显，但对于高数值孔径系统，旁瓣强度较大。通过这种方式，可以提高高数值孔径系统的 SIL 的分辨率和焦深。
The intensity distribution in near-field optical data storage with a solid immersion lens (SIL) and a binary phase-only diffractive super-resolution element (DSE) is expressed in a single definite integral by using angular spectrum theory. The super-resolution of binary two-zone phase DSEs for SIL systems is numerically studied for low and high numerical aperture (NA) systems. The results for the low-NA systems show that optimizing the zone boundary and phase of binary two-zone phase DSEs can decrease the spot size. The Strehl ratio, sidelobe intensity and axial characteristic length are also discussed. In addition, a binary two-zone phase filter can change the position of focus that shifts from the SIL–air interface to air, but the spot size increases. For the high-NA systems, the y- and z-polarized components of the transmitted field increase as the boundary and depth of phase of the DSE increase. When the phase boundary is smaller and the depth of phase depth is close to π, super-resolving effect of DSE is more obvious but the intensity of sidelobes is larger for the high-NA system. In this way, it may be possible to improve both the resolution and focal depth of the SIL with high-NA systems.