This paper analyses the algebraic and physical properties of the spin and orbital angular momenta of light in the quantum mechanical framework. The consequences of the fact that these are not angular momenta in the quantum mechanical sense are worked out in mathematical detail. It turns out that the spin part of the angular momentum has continuous eigenvalues. Particular attention is given to the paraxial limit, and to the definition of Laguerre–Gaussian modes for photons as well as classical light fields taking full account of the polarization degree of freedom.

中文翻译：

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光的自旋和轨道角动量的性质

本文在量子力学框架下分析了光的自旋和轨道角动量的代数和物理性质。这些不是量子力学意义上的角动量这一事实的后果是在数学上详细计算出来的。事实证明，角动量的自旋部分具有连续的特征值。特别注意近轴极限，以及光子的拉盖尔-高斯模式的定义以及充分考虑偏振自由度的经典光场。