近日，清华大学的杨原牧及其研究团队取得一项新进展。经过不懈努力，他们研制出用于单发椭圆偏振光谱系统的超表面阵列。相关研究成果已于2024年4月10日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队成功展示了一个紧凑的基于超表面阵列的光谱椭圆偏振系统。该系统无需任何机械运动，即可实现单发光谱偏振检测，从而准确测定薄膜性质。研究人员巧妙结合了具有高度各向异性和多样化光谱响应的硅基超表面阵列，实现了对薄膜反射光全斯托克斯偏振谱的高保真度重建。

进一步，通过将测量结果拟合到合适的材料模型中，系统能够高精度地确定薄膜的厚度和折射率。这一创新性的研究方法为构建紧凑且鲁棒的光谱椭圆偏振系统提供了新途径，为薄膜性质的高通量测量开辟了广阔前景。

据悉，光谱椭圆偏振技术是一种广泛应用于薄膜厚度和折射率测量的有效方法。大多数传统的椭圆偏振仪利用机械旋转偏振器，和基于光栅的光谱仪进行光谱偏振检测。

附：英文原文

Title: Metasurface array for single-shot spectroscopic ellipsometry

Author: Wen, Shun, Xue, Xinyuan, Wang, Shuai, Ni, Yibo, Sun, Liqun, Yang, Yuanmu

Issue&Volume: 2024-04-10

Abstract: Spectroscopic ellipsometry is a potent method that is widely adopted for the measurement of thin film thickness and refractive index. Most conventional ellipsometers utilize mechanically rotating polarizers and grating-based spectrometers for spectropolarimetric detection. Here, we demonstrated a compact metasurface array-based spectroscopic ellipsometry system that allows single-shot spectropolarimetric detection and accurate determination of thin film properties without any mechanical movement. The silicon-based metasurface array with a highly anisotropic and diverse spectral response is combined with iterative optimization to reconstruct the full Stokes polarization spectrum of the light reflected by the thin film with high fidelity. Subsequently, the film thickness and refractive index can be determined by fitting the measurement results to a proper material model with high accuracy. Our approach opens up a new pathway towards a compact and robust spectroscopic ellipsometry system for the high throughput measurement of thin film properties.

DOI: 10.1038/s41377-024-01396-3

Source: https://www.nature.com/articles/s41377-024-01396-3