Nevertheless, none of those methods can be applied to analyze and calculate the scattering of particles for the nonplane
waves such as the Gaussian beam incidence or a top-hat beam.
However, these numerical methods are not adequate if two areas of the same nonplane
surface (example: sag-deformation sheet) exchange energy by radiation.
"We have this nonplane
wave that hits the deformable mirror, but by the time it bounces off, it's a plane wave again," says Acton.