Koivurova Matias, Partanen Henri, Lahyani Julien, Cariou Nathan, Turunen Jari
Opt Express. 2019 Mar 4;27(5):7738-7750. doi: 10.1364/OE.27.007738.
We present modified scanning-type wavefront folding interferometers (WFIs), which allow spatial coherence measurements of non-uniformly correlated fields, where the degree of coherence is a function of two absolute spatial coordinates instead of coordinate separation only (Schell model). As an alternative to conventional prism-based WFI implementations, we introduce a scheme based on reflections by three mirrors. This setup allows us to avoid obstructions due to prism corners, and it is remarkably robust to polarization effects. Experimental results on measurement of fields that do not obey the Schell model are provided with the three-mirror WFI, and the results are compared to those obtained with a Young's interferometer realized using a digital micromirror device.
我们展示了改进的扫描型波前折叠干涉仪（WFI），它能够对非均匀相关场进行空间相干性测量，其中相干度是两个绝对空间坐标的函数，而不仅仅是坐标间距的函数（谢尔模型）。作为传统基于棱镜的WFI实现方式的替代方案，我们引入了一种基于三个反射镜反射的方案。这种设置使我们能够避免因棱镜角造成的阻碍，并且对偏振效应具有显著的鲁棒性。给出了使用三反射镜WFI对不服从谢尔模型的场进行测量的实验结果，并将结果与使用数字微镜器件实现的杨氏干涉仪所获得的结果进行了比较。
