Nienhuis Gerard
Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
Philos Trans A Math Phys Eng Sci. 2017 Feb 28;375(2087). doi: 10.1098/rsta.2015.0443.
The insight that a beam of light can carry orbital angular momentum (AM) in its propagation direction came up in 1992 as a surprise. Nevertheless, the existence of momentum and AM of an electromagnetic field has been well known since the days of Maxwell. We compare the expressions for densities of AM in general three-dimensional modes and in paraxial modes. Despite their classical nature, these expressions have a suggestive quantum mechanical appearance, in terms of linear operators acting on mode functions. In addition, paraxial wave optics has several analogies with real quantum mechanics, both with the wave function of a free quantum particle and with a quantum harmonic oscillator. We discuss how these analogies can be applied.This article is part of the themed issue 'Optical orbital angular momentum'.
1992年，人们意外地发现光束能够在其传播方向上携带轨道角动量（AM）。然而，自麦克斯韦时代以来，电磁场的动量和角动量的存在就已为人所知。我们比较了一般三维模式和傍轴模式下的角动量密度表达式。尽管这些表达式具有经典性质，但从作用于模式函数的线性算符角度来看，它们具有引人联想的量子力学表象。此外，傍轴波动光学与真正的量子力学有若干相似之处，既与自由量子粒子的波函数相似，也与量子谐振子相似。我们讨论了如何应用这些相似之处。本文是主题为“光学轨道角动量”的特刊的一部分。
