用于并行激光直写的连续深浮雕衍射透镜阵列研究

研究了一种用于并行激光直写的连续深浮雕衍射透镜阵列方法.该方法采用连续浮雕衍射透镜阵列替换传统并行激光直写中的物镜阵列,在兼顾系统分辨力基础上,克服了波带片等衍射透镜阵列衍射效率低的缺点;同时因采用深浮雕结构优化环带宽度,可降低阵列的制作难度.针对并行激光直写系统阵列F/#小的特点,在建立连续深浮雕衍射透镜阵列非旁轴近似聚焦模型基础上,设计、制作和测试了波长为441.6 nm,F/#为7.5的连续深浮雕衍射透镜阵阵列.测试结果表明:该阵列的衍射效率优于70%,远高于波带片阵列的40%.

Diffractive Optical Elements Arrays with Continuous Deep-relief for Maskless Lithography

Diffractive optical elements (DOEs) arrays with continuous deep-relief for maskless lithography is investigated. In comparison with such conventional DOEs arrays as zone-plates array used for maskless lithography,the DOEs with continuous deep-relief make it possible to further increase NA at a high diffraction focusing efficiency,and deep relief can be used to optimize relief depth and zone period to make the fabrication of arrays easy. To verify its validity, continuous-deep-relief DOEs arrays with F/7.5 are designed, fabricated and characterized for maskless lithography. Experimental results indicate that a diffraction efficiency of over 70% can be achieved at normal incidence and writing laser wavelength of 441.6 nm,which is much higher than the diffraction efficiency of 40% for a zone-plates array.