针对现有基于微球的超分辨成像系统中液体浸没方式的不稳定性和繁琐性, 提出采用介质层来替代液体层, 制成含有单层密排微球的薄膜.研究折射率较低的二氧化硅微球和折射率较高的钛酸钡微球浸没在三种不同液体中时的成像特性, 设计并制备了一种由单层密排的钛酸钡微球和聚二甲基硅氧烷(PDMS)软膜构成的薄膜, 并开展了相应的超分辨成像实验.结果表明: 当液体折射率在1.33~1.548之间时, 二氧化硅微球只有在半浸没时才能分辨出小于衍射极限的样品特征, 而钛酸钡微球则需要全浸没才能实现超分辨成像.在600 nm中心波长的照明下, 利用该薄膜可以清晰地分辨出周期为278 nm, 占空比为1: 1的硅结构光栅.

A thin-film was proposed for optical super-resolution imaging,which substitute the liquid layer with a soft mold in the original dielectric microsphere based super-resolution imaging.The imaging character of silica and barium titanate glass microsphere immersed in three different liquid were investigated.And a thin-film was prepared which contains a layer of closely-arranged barium titanate glass microsphere embedded in a transparent polydimethylsiloxane soft mold.The result shows that the silica microsphere can discern the sample feature below the diffraction limit only it is semi-immersed in the liquid with refractive index lies in the range 1.33~1.548.However,the barium titanate glass microsphere should be fully immersed to achieve super-resolution imaging.The experiment is also taken to verify the feasibility of the thin-film based super-resolution imaging.A grating with period of 278 nm can be clearly discerned at the illuminated wavelength of 600 nm.