File:Multiple scattering interference.gif

Summary

Description
English: A single point scatterer illuminated by a plane wave will produce a spherical wave, but if you increase the number of scatterers the interference between the scattered waves will quickly produce an apparently random speckle pattern.
Date
Source https://twitter.com/j_bertolotti/status/1128594815640379398
Author Jacopo Bertolotti
Permission
(Reusing this file)
https://twitter.com/j_bertolotti/status/1030470604418428929

Mathematica 11.0 code

\[Lambda] = 1;
k0 = (2 \[Pi])/\[Lambda];
\[Alpha] = 4/(k0^2 I);
\[Sigma] = (k0^3 Norm[\[Alpha]]^2)/4 // N;
G[r_] := N[I/4 HankelH1[0, k0 Norm[r] ]];
source[x_] := E^(I k0 x); (*Plane wave illuminating the scatterers*)
p0 = GraphicsRow[{
   DensityPlot[Re[source[x] ], {x, -10, 10}, {y, -10, 10}, PlotPoints -> 50, Frame -> False, PlotLabel -> "Re[E]", LabelStyle -> {Black, Bold}],
   DensityPlot[Abs[source[x]]^2, {x, -10, 10}, {y, -10, 10}, PlotPoints -> 50, ColorFunction -> "AvocadoColors", PlotRange -> {0, 1}, Frame -> False, PlotLabel -> "|E\!\(\*SuperscriptBox[\(|\), \(2\)]\)", 
    LabelStyle -> {Black, Bold}]
   }, ImageSize -> Large];
scatterers = {{0, 0}};
plots = Reap[Do[
     dim = Dimensions[scatterers][[1]];
     E0 = Table[N[source[scatterers[[j, 1]] ]], {j, 1, dim}] ;(*source field on each scatterer*)
     iME = Inverse@Table[If[k == j, 1, \[Alpha] k0^2 G[scatterers[[j]] - scatterers[[k]] ] ], {j, 1, dim}, {k, 1, dim}];
     Es = iME.E0 ;(*Total field on each scatterer*)
     Etot = source[x] + \[Alpha] k0^2 Sum[Es[[j]]*G[{x, y} - scatterers[[j]]], {j, 1, dim}];
     Sow@GraphicsRow[{
        DensityPlot[Re[Etot ], {x, -10, 10}, {y, -10, 10}, PlotPoints -> 50, Epilog -> {Black, PointSize[0.02], Point[scatterers]}, Frame -> False, PlotLabel -> "Re[E]", LabelStyle -> {Black, Bold}]
        ,
        DensityPlot[Abs[Etot ]^2, {x, -10, 10}, {y, -10, 10}, PlotPoints -> 50, ColorFunction -> "AvocadoColors", PlotRange -> {0, 5}, Epilog -> {White, PointSize[0.02], Point[scatterers]}, Frame -> False, 
         PlotLabel -> "|E\!\(\*SuperscriptBox[\(|\), \(2\)]\)", LabelStyle -> {Black, Bold}]
        }, ImageSize -> Large];
     AppendTo[scatterers, RandomReal[{-7, 7}, 2]];
     , 20];][[2, 1]];
ListAnimate[plots]

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
Creative Commons CC-Zero This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.
The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.

Category:CC-Zero#Multiple%20scattering%20interference.gifCategory:Self-published work
Category:Scattering Category:Animations of interference Category:Images with Mathematica source code Category:Animated GIF files
Category:Animated GIF files Category:Animations of interference Category:CC-Zero Category:Images with Mathematica source code Category:Scattering Category:Self-published work