Abouraddy Ayman F, Kagalwala Kumel H, Saleh Bahaa E A
Opt Lett. 2014 Apr 15;39(8):2411-4. doi: 10.1364/OL.39.002411.
The two-point coherence of an electromagnetic field is represented completely by a 4×4 coherency matrix G that encodes the joint polarization-spatial-field correlations. Here, we describe a systematic sequence of cascaded spatial and polarization projective measurements that are sufficient to tomographically reconstruct G--a task that, to the best of our knowledge, has not yet been realized. Our approach benefits from the correspondence between this reconstruction problem in classical optics and that of quantum state tomography for two-photon states in quantum optics. Identifying G uniquely determines all the measurable correlation characteristics of the field and, thus, lifts ambiguities that arise from reliance on traditional scalar descriptors, especially when the field's degrees of freedom are correlated or classically entangled.
电磁场的两点相干性完全由一个4×4相干矩阵G表示，该矩阵编码了联合偏振-空间场相关性。在此，我们描述了一系列级联的空间和偏振投影测量的系统序列，这些测量足以对G进行层析重建——据我们所知，这一任务尚未实现。我们的方法得益于经典光学中的这一重建问题与量子光学中双光子态的量子态层析成像问题之间的对应关系。确定G唯一地决定了场的所有可测量相关特性，从而消除了因依赖传统标量描述符而产生的模糊性，特别是当场的自由度相关或经典纠缠时。
