Wang Cai, Chen Xiuguo, Chen Chao, Sheng Sheng, Song Lixuan, Gu Honggang, Jiang Hao, Zhang Chuanwei, Liu Shiyuan
Opt Express. 2021 Sep 27;29(20):32158-32168. doi: 10.1364/OE.432611.
Computational super-resolution is a novel approach to break the diffraction limit. The Mueller matrix, which contains full-polarization information about the morphology and structure of a sample, can add super-resolution information and be a promising way to further enhance the resolution. Here we proposed a new approach called Mueller-matrix scattered-field microscopy (MSM) that relies on a computational reconstruction strategy to quantitatively determine the geometrical parameters of finite deep sub-wavelength nanostructures. The MSM adopts a high numerical-aperture objective lens to collect a broad range of spatial frequencies of the scattered field of a sample in terms of Mueller-matrix images. A rigorous forward scattering model is established for MSM, which takes into account the vectorial nature of the scattered field when passing through the imaging system and the effect of defocus in the measurement process. The experimental results performed on a series of isolated Si lines have demonstrated that MSM can resolve a feature size of λ/16 with a sub-7 nm accuracy. The MSM is fast and has a great measurement accuracy for nanostructures, which is expected to have a great potential application for future nanotechnology and nanoelectronics manufacturing.
计算超分辨率是一种突破衍射极限的新方法。穆勒矩阵包含有关样品形态和结构的全偏振信息，可以添加超分辨率信息，是进一步提高分辨率的一种有前途的方法。在此，我们提出了一种名为穆勒矩阵散射场显微镜（MSM）的新方法，该方法依靠计算重建策略来定量确定有限深度亚波长纳米结构的几何参数。MSM采用高数值孔径物镜，根据穆勒矩阵图像收集样品散射场的广泛空间频率。为MSM建立了严格的前向散射模型，该模型考虑了散射场在通过成像系统时的矢量性质以及测量过程中的离焦效应。在一系列孤立的硅线实验结果表明，MSM可以以低于7纳米的精度分辨出λ/16的特征尺寸。MSM速度快，对纳米结构具有很高的测量精度，有望在未来纳米技术和纳米电子制造中具有巨大的潜在应用价值。
