File:Optical Memory Effect.gif

Summary

Description
English: A scattering screen scrambles the incident light producing a speckle pattern. But if the incident beam is tilted, to a first order also the resulting speckle is tilted by the same amount, and change slowly with the angle.
Date
Source https://twitter.com/j_bertolotti/status/1285225731782520832
Author Jacopo Bertolotti
Permission
(Reusing this file)
https://twitter.com/j_bertolotti/status/1030470604418428929
GIF development
InfoField

Mathematica 12.1 code

ReMapC[x_] := RGBColor[(Cos[2 \[Pi] x] + 1)/2 UnitStep[x - 0.5], 0, (Cos[2 \[Pi] x] + 1)/2 UnitStep[0.5 - x]];
\[Lambda] = 0.1; k0 = (2 \[Pi])/\[Lambda] // N;
dim = 2^8 + 1;
\[Sigma] = dim/10;
disorder = Table[E^(I RandomReal[{0, 2 \[Pi]}]), {x, 1, dim}, {y, 1, dim}];
p0 = Table[
   U0 = Table[ E^(-(((x - dim/2)^2 + (y - dim/2)^2)/(2 \[Sigma] ^2))) E^(I k0 (Sin[\[Theta]] x)), {x, 1, dim}, {y, 1, dim}];
   A0 = RotateRight[InverseFourier[U0], {(dim - 1)/2, (dim - 1)/2}];
   evo = Table[
     H = Table[E^(I Sqrt[k0^2 - (kx - ((dim + 1)/2))^2 - (ky - ((dim + 1)/2))^2] z), {kx, 1, dim}, {ky, 1, dim}];
     U = Fourier[RotateLeft[A0*H, {(dim - 1)/2, (dim - 1)/2}] ]
     , {z, 0, 10 \[Lambda], \[Lambda]/4}];
   U1 = U0*disorder;
   A1 = RotateRight[InverseFourier[U1], {(dim - 1)/2, (dim - 1)/2}];
   evos = Table[
     H = Table[E^(I Sqrt[k0^2 - (kx - ((dim + 1)/2))^2 - (ky - ((dim + 1)/2))^2] z), {kx, 1, dim}, {ky, 1, dim}];
     U = Fourier[RotateLeft[A1*H, {(dim - 1)/2, (dim - 1)/2}] ]
     , {z, 0, 10 \[Lambda], \[Lambda]/4}];   
   Grid[{{
      ListPlot[Abs[evos[[-1, All, Round[Dimensions[evo][[3]]/2]]] ]^2 , Joined -> True, PlotRange -> All, AspectRatio -> 0.1, ImageSize -> Large, Axes -> False, PlotStyle -> {Black, Thick}]
      }, {
      ArrayPlot[Abs[evos[[All, All, Round[Dimensions[evo][[3]]/2]]] ]^2/Max[Abs[evos[[20 ;; -1, All, Round[Dimensions[evos][[3]]/2]]]^2] ], ColorFunction -> "SunsetColors", ColorFunctionScaling -> False, Frame -> False, PlotRangePadding -> None , ImageSize -> Large, DataReversed -> True]
      }, {
      ArrayPlot[Abs[evo[[All, All, Round[Dimensions[evo][[3]]/2]]] ]^2, ColorFunction -> "SunsetColors", ColorFunctionScaling -> False, Frame -> False, PlotRangePadding -> None, ImageSize -> Large , DataReversed -> {False, True}]
      }}, Spacings -> 0]
   , {\[Theta], -\[Pi]/800, \[Pi]/800, \[Pi]/(800*20)}];
ListAnimate[Join[p0, Reverse[p0]]]

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#Optical%20Memory%20Effect.gifCategory:Self-published work
Category:Animations of optics Category:Scattering Category:Animations of photonics Category:Images with Mathematica source code Category:Animated GIF files
Category:Animated GIF files Category:Animations of optics Category:Animations of photonics Category:CC-Zero Category:Images with Mathematica source code Category:PNG created with Mathematica Category:Scattering Category:Self-published work