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# scriptfile: usr_importnk_3d.lsf
#
# description: The first section of this file shows how
#     to create a text file with 3D n,k data. This script also works for anisotropy.
#
#
#     The second section shows how to import n,k data
#     from a text file into an import object.  
#
# Copyright 2015, Lumerical Solutions, Inc.
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clear;
anisotropic = 1;

###################################################################################
# Section 1
# export n,k data to a text file

# generate a volume of refractive index data
x = linspace(-10,10,40);
y = linspace(-10,10,35);
z = linspace(-10,10,20); # set resolution to 2 for 2D
X = meshgrid3dx(x,y,z);
Y = meshgrid3dy(x,y,z);
Z = meshgrid3dz(x,y,z);

if (anisotropic){
n=matrix(length(x),length(y),length(z),3); # a matrix for all 3 directions, anisotropic
n(1:length(x), 1:length(y), 1:length(z),1) = 1.5 + sin(2*pi*X/6)*exp(-((X^2+Y^2+Z^2)/5^2)) + 0.1i*cos(Y); # x direction
n(1:length(x), 1:length(y), 1:length(z),2) = 1.5 + 0.1i*sin(2*pi*X/6)*exp(-((X^2+Y^2+Z^2)/5^2)) + sin(Y); # y direction
n(1:length(x), 1:length(y), 1:length(z),3) = 1.5 + cos(2*pi*Y/6)*exp(-((X^2+Y^2+Z^2)/10^2)) + 0.2i*sin(Y);# z direction
}else{
n=matrix(length(x),length(y),length(z)); # isotropic
n(1:length(x), 1:length(y), 1:length(z)) = 1.5 + sin(2*pi*X/6)*exp(-((X^2+Y^2+Z^2)/5^2)) + 0.1i*cos(Y); 
}

# choose a filename and delete the file if it exists
filename = "usr_importnk_3d.txt";
rm(filename);

# write the header
write(filename,num2str(length(x)) + " " + num2str(x(1)) + " " + num2str(x(length(x))));
write(filename,num2str(length(y)) + " " + num2str(y(1)) + " " + num2str(y(length(y))));
write(filename,num2str(length(z)) + " " + num2str(z(1)) + " " + num2str(z(length(z))));

# copy the data into a temporary vector
if (anisotropic) {
temp_mat = matrix(length(x)*length(y)*length(z),6);
}else{
temp_mat = matrix(length(x)*length(y)*length(z),2);
}
nn = size(n);
pos = 0;
for(k=1:nn(3)) {
  for(j=1:nn(2)) {
    for(i=1:nn(1)) {
      pos = pos + 1; 
       if (anisotropic){     
      temp_mat(pos,1) = real( n(i,j,k,1) );
      temp_mat(pos,2) = imag( n(i,j,k,1) );
      temp_mat(pos,3) = real( n(i,j,k,2) );
      temp_mat(pos,4) = imag( n(i,j,k,2) );
      temp_mat(pos,5) = real( n(i,j,k,3) );
      temp_mat(pos,6) = imag( n(i,j,k,3) );
     } else {
      temp_mat(pos,1) = real( n(i,j,k) );
      temp_mat(pos,2) = imag( n(i,j,k) );
     }
   }
 }
  ?"Completed " + num2str(k/nn(3)*100) + "%";
}

# write the vector to file
write(filename,num2str(temp_mat));

# End of section 1
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###################################################################################
# Section 2
# load n,k data from a text file into import object

# add an import object
addimport;


# choose the desired options
filename = "usr_importnk_3d.txt";
file_units = "microns";
x0 = 0;
y0 = 0;
z0 = 0;
reverse_index_order = 0; # choose 1 to reverse order of indices as read from file

# import the data from file
importnk(filename,file_units,x0,y0,z0,reverse_index_order);

# End of section 2
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