Briefly looked at your code.
At the bottom part of your code:

fielduno = # - fielduno[[1, 1]] & /@ fielduno;

{out, c2, c0} = rhod[{0, 0}, {0, 0}, R, 2*H];

fielduno = 
  fielduno + 
   KroneckerProduct[ty*RandomVariate[NormalDistribution[], n], 
     tx*RandomVariate[NormalDistribution[], m]]*Sqrt[2*c2];

after that the following will be enough:

data = Table[fielduno[[i, j]], {i, n/2}, {j, m/2}];

ListPlot3D[data, Mesh -> None, PlotTheme -> "Detailed", 
 ColorFunction -> ColorData["Rainbow"], DataRange -> {{0, 1}, {0, 1}},
  RegionFunction -> Function[{x, y, z}, Norm[{x, y}] < 1]]

Hello Sam after searching for help to get the graphic as your ask here it, I must remind you that I not is much of matlab, did my notebook of mathematica with the help of some friends at the University but they could not help me to find my failure in the graph

I hope someone can help me

Jaebum Jung many thanks for helping me to solve my problem, also thank you to devote your time to find the bug in my code, thanks to your help I could see a beautiful graph.