微球透镜亚波长显微成像远场特性实验研究

Far-field Sub-wavelength microscopic imaging properties of microsphere lenses

利用低折射率的二氧化硅和高折射率的钛酸钡微球透镜对蓝光刻录光碟的亚波长表面结构进行了显微成像实验,观察了两类微球在空间上与样品表面分离时的成像特性。实验结果表明:在微球透镜与样品表面分离0~6μm的空间范围内,微球透镜对亚波长纳米结构仍具有分辨能力,且放大作用明显。通过实验比较,发现在浸没方式、放大率大小、成像尺度范围等方面,高折射微球表现出不同于低折射微球的远场特性。微球透镜的电场强度仿真表明,微球成像特性受电场分布的影响明显,为进一步揭示微球超分辨显微成像的机理提供了依据。

The Silica microsphere lens with low refractive index and BaTiO_(3) microsphere lenses with high refractive index are used to image the sub-wavelength surface structure of data-recorded Blu-ray disc.The imaging properties of the microsphere lenses when they are spatially separated from the surface of the sample are observed in the experiments.The experimental results illustrate that the sub-wavelength surface patterns can still be resolved by the microsphere lens with a significant magnification,when the distance between the microsphere lens and the sample surface is about 0~6μm.The comparative experiment shows that the high-index microsphere perform different imaging properties in immersing mode,magnification and imaging scale,et al.The simulation results of electric filed distribution of the microsphere lenses illuminate that the imaging properties of microspher lenses are greatly effected by the electric filed distribution,which provide basic for the revealing of the mechanism of super resolution of microsphere lenses.