We provide a statistically robust and accurate framework to measure and track the polarisation state of light employing Hong-Ou-Mandel interference. This is achieved by combining the concepts of maximum likelihood estimation and Fisher information applied to photon detection events. Such an approach ensures that the Cramér-Rao bound is saturated and changes to the polarisation state are established in an optimal manner. Using this method, we show that changes in the linear polarisation state can be measured with 0.6 arcminute precision (0.01 degrees).

中文翻译：

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通过Hong-Ou-Mandel干涉仪跟踪光的偏振态。

我们提供一个统计上可靠且准确的框架，以利用Hong-Ou-Mandel干涉来测量和跟踪光的偏振状态。这是通过将最大似然估计和应用于光子检测事件的Fisher信息相结合来实现的。这种方法可确保Cramér-Rao饱和，并以最佳方式建立偏振态的变化。使用这种方法，我们证明可以以0.6弧分/分钟（0.01度）的精度测量线性极化状态的变化。