Ronchi L
Appl Opt. 1978 Aug 15;17(16):2516-8. doi: 10.1364/AO.17.002516.
Approximate solutions of the wave equation are investigated, which can be considered as Gaussian beams affected by third-order spherical aberration. In practical cases, such beams are good approximations to the beams emerging from media whose square refractive index is described by a fourth-degree polynomial of the transverse coordinate. The measure of their spherical aberration could be a means for the determination of the coefficient of the fourth-order term in the expression of the square refractive index of the gradedindex medium.
研究了波动方程的近似解，其可被视为受三阶球差影响的高斯光束。在实际情况中，此类光束是对从平方折射率由横向坐标的四次多项式描述的介质中出射的光束的良好近似。它们的球差度量可作为确定渐变折射率介质平方折射率表达式中四阶项系数的一种手段。
