使用可变角度偏振器方法测量克尔旋转
Measurement of Kerr rotation using a variable-angle polarizer method
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中文总结 AI 辅助
研究利用可变角度偏振器方法测量钴薄膜克尔旋转，通过对不同偏振器角度的\(p\)和\(s\)偏振激光测量及数据拟合，准确获得克尔旋转角，消除单点测量不确定性，测量结果与文献估计值吻合。
中文摘要 AI 辅助
磁光克尔效应（MOKE）在偏振光从磁化表面反射时发生，导致偏振角和状态的微小变化。克尔旋转角的测量已很成熟，通常在偏振器 - 分析器几何结构中接近零配置进行。然而，精确测量仍是挑战，因为该效应复杂地依赖于多个光学参数。我们在钴薄膜上对不同偏振器角度的\(p\)和\(s\)偏振激光进行了一系列纵向磁光克尔效应测量，使用渥拉斯顿棱镜测量反射偏振光的正交分量。通过将正交光分量的解析表达式拟合到不同偏振器角度测量的平均强度和MOKE信号来获得克尔旋转角。我们的分析得出，对于633nm激光在45°入射角时，\(p(s)\) - 克尔旋转为0.46（0.65）毫弧度，与使用现有文献数据对钴的估计值非常吻合。该方法不仅非常精确，还消除了克尔旋转单点测量中固有的不确定性。
英文摘要
The magneto-optical Kerr effect (MOKE) occurs when polarized light reflects from a magnetized surface, causing a small change in the polarization angle and state. Measurement of the rotation in the angle (Kerr rotation) is well established and typically performed close to the null configuration in a polarizer-analyzer geometry. However, accurate measurement always remains a challenge and as the effect depends intricately on several optical parameters. Here we performed a series of longitudinal magneto-optical Kerr effect (MOKE) measurements on $p$ and $s$ polarized laser light at various polarizer angles on a Cobalt thin film and measured the orthogonal components of the reflected polarized light using a Wollaston prism. Analytical expressions for the orthogonal light components were fitted to the average intensity and the MOKE signal measured at different polarizer angles to obtain the Kerr roations. Our analysis yielded a $p (s)$-Kerr rotation of 0.46 (0.65) milliradians for a 633~nm laser at 45$^\circ$ angle of incidence, which agrees very well with our estimated value for Co using available literature data. Apart from being very accurate, the advantage of the process is that it eliminates the inherent uncertainties in single-point measurements of the Kerr rotation.
