波动方程的简谐平面波解，在建立了波动方程之后，我们来讨论其解的形式及其特性-Simple harmonic plane wave solutions of wave equation, wave equation, we discuss its solution in the form of its characteristics

applied optics上的一篇关于coaxial fiber的文章,在解析法求解光纤时，对光纤建立模型有帮助。-A mathematical solution of the wave equation for coaxial fibers having four different refractive-index profiles is presented.