Light, sound, and electron transmission through a single hole in a screen of finite thickness
The hole has circular shape.
For light, the film is made of perfect conductor and the transmission is calculated by solving Maxwell's equations.
For sound, the film is made of a hard solid and we solve the Helmholz equation with vanishing normal derivative at the boundaries.
For electrons, the film represents an infinite potential region and we solve the Helmholz equation with vanishing wave function at the boundaries.
The transmission cross section is normalized to the area of the hole.
For more details on light transmission through a single hole, see
F. J. García de Abajo, Opt. Express 10, 1475 (2002) and
F. J. García de Abajo, Rev. Mod. Phys. 79, 1267 (2007).
For a comparison of light, sound, and electron transmission, see
F. J. García de Abajo, H. Estrada, and F. Meseguer, New J. Phys. 11, 093013 (2009).