Zahra Naila, Mizutani Yasuhiro, Uenohara Tsutomu, Takaya Yasuhiro
Department of Mechanical Engineering, The University of Osaka, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Instrumentation, Control, and Automation Research Group, Faculty of Industrial Technology, Institut Teknologi Bandung, Ganesa 10, Bandung, West Java, 40132, Indonesia.
Sci Rep. 2025 Apr 15;15(1):12911. doi: 10.1038/s41598-025-95988-7.
This paper presents a novel method for the measurement of nanometer-scale surfaces. The proposed technique takes advantage of the spin hall effect of light (SHEL), which occurs as a sub-wavelength beam shift due to the spin-orbit interaction of light when it interacts with non-homogeneous optical media. Governed by the conservation of total angular momentum, the SHEL offers a sensitive approach to detecting the variations of optical properties at an interface. "SHEL Ellipsometry" applies weak measurement principles to observe beam shifts, analogous to traditional ellipsometry, which analyzes the polarization states of incident and reflected light. In ellipsometry, a homogeneous sample with surface roughness less than a tenth of the wavelength can be modeled as a thin film characterized by an equivalent thickness and refractive index. By measuring the transverse shifts of the reflected beam and using raster scanning, SHEL Ellipsometry can map the two-dimensional surface roughness distribution, showing significant potential for nanometer-scale surface measurement.
本文提出了一种测量纳米尺度表面的新方法。所提出的技术利用了光的自旋霍尔效应（SHEL），当光与非均匀光学介质相互作用时，由于光的自旋轨道相互作用，会发生亚波长光束位移，从而产生这种效应。受总角动量守恒的支配，SHEL提供了一种灵敏的方法来检测界面处光学性质的变化。“SHEL椭偏仪”应用弱测量原理来观察光束位移，类似于传统椭偏仪，传统椭偏仪分析入射光和反射光的偏振态。在椭偏测量中，表面粗糙度小于波长十分之一的均匀样品可以被建模为具有等效厚度和折射率的薄膜。通过测量反射光束的横向位移并使用光栅扫描，SHEL椭偏仪可以绘制二维表面粗糙度分布，在纳米尺度表面测量方面显示出巨大潜力。
