基于激光受激辐射损耗原理的远场光学超分辨成像技术,当圆形入射高斯激光经过涡旋相位板调制后,将转变为中心光强为零的圆环形光束,该形状的激光束与光敏聚合物作用,能够制备出具有一定功能的纳米结构。介绍了自主搭建的基于圆环连续激光光源的激光直写系统,以及利用该系统研制的复合纳米结构。当光源为532 nm连续激光输出时,与正性光刻胶作用,得到直径〈50 nm的纳米柱复合结构,以及整齐均匀的纳米柱阵列结构;与负性光刻胶作用,得到直径〈100 nm的纳米通道,以及整齐均匀的中央有纳米通道的微米柱复合结构阵列。当光源为405 nm连续光纤激光时,与正性光刻胶作用,也得到了直径小至153 nm的纳米柱复合结构及其阵列。这些纳米结构的基本单元尺寸都突破了光学“阿贝衍射极限”的限制,具有实用潜力。
Based on principle of laser stimulated emission deplection, far field optical super-resolution imaging technique, modulated by vortex phase plate, incident Gaussian laser will be transformed into a donut-shaped light beam with zero central intensity. Functional nanoscale structures will be obtained when laser beam with donut-shaped laser beam irradiates onto photosensitive polymer.This paper presents laser direct lithographing system based on CW laser beam, as well as its applications in preparation of composite nanostructures. When light source is 532 nm CW laser output, a composite nanopillar with pillar’s diameter less than 50 nm and pillar arrays is fabricated with a positive photo resist. While composite structure of nanochannel with 〈100 nm inner diameter in center of micropillar, corresponding arrays are fabricated with a negative photo resist. In addition, when laser source is continuous 405 nm fiber laser, composite nanopillar with 153 nm diameter and various arrays are also achieved with positive photo resist. Basic units of these composite nanostructures are all broken through optical Abbe’s diffraction limit. and have practical potential.