We propose a method for finding two-dimensional spatial modes of thermal field through a direct measurement of the field intensity and an offline analysis of its spatial fluctuations. Using this method, in a simple and efficient way we reconstruct the modes of a multimode fiber and the spatial Schmidt modes of squeezed vacuum generated via high-gain parametric down-conversion. The reconstructed shapes agree with the theoretical results.

中文翻译：

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重构经典光和量子光的二维空间模式

我们提出了一种通过直接测量场强并对其空间涨落进行离线分析来寻找二维热场空间模式的方法。使用这种方法，我们以一种简单有效的方式重构了通过高增益参数下变频产生的多模光纤的模和压缩真空的空间施密特模。重建的形状与理论结果相符。