How to make a program more efficient by changing for loops

Hi, I know this isn't really a question but I would like to learn how to make my program more efficient:

function [] = mapa

m=60;
n_re=linspace(1,6,m);
n_im=linspace(0,6,m);
z=zeros(m,m);
load('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Samples\experimental_values_M2612')
tic

en=1; %para cambiar subplot
er=2; %cambiar la linea de experimental values (wavelength)
global lambda0;
for lambda0=[450,500,520,546,568,600,632,650,694];

for v=1:18

      d=Experimental_values(v,1)
      Cexp=Experimental_values(v,er) %el numero depende de que columna de la tabla es:2=450nm,
         %3=500nm,4=520nm,5=546nm, 6=568nm, 7=600nm, 8=632nm, 9=650nm, 10=694nm,
         %HAY QUE CAMBIAR TAMBIEN LAMBDA0!!

for i=1:m
        for j=1:m
        n=n_re(i)+1i*n_im(j);

          z(i,j)= cx2(lambda0,d,n,Cexp);
          save(['Z_' num2str(v)],'z')
  %--------------------------------------------------------------------------%  
  %--------------------------------------------------------------------------%
          %guarda con un valor distinto cada vez. Tengo que borrar los 
          %archivos guardados si voy a hacer menos puntos (m) o si voy a
          %poner menos datos (de 18 por ejemplo)!Los archivos Z_x y MeanZ y
          %TotalZ.
  %--------------------------------------------------------------------------%      
  %--------------------------------------------------------------------------%        
          end

toc        
end

end

%dependiendo del numero de datos que tengamos tenemos que quitar algunos de
%los siguientes load, y cambiar TotalZ y el numero por el que divide MeanZ

load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_1')
Z_1=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_2')
Z_2=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_3')
Z_3=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_4')
Z_4=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_5')
Z_5=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_6')
Z_6=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_7')
Z_7=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_8')
Z_8=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_9')
Z_9=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_10')
Z_10=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_11')
Z_11=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_12')
Z_12=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_13')
Z_13=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_14')
Z_14=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_15')
Z_15=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_16')
Z_16=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_17')
Z_17=z;
load ('C:\Users\Weinberg\Desktop\Prueba matlab\Pcolor_V1\Z_18')
Z_18=z;

TotalZ=Z_1+Z_2+Z_3+Z_4+Z_5+Z_6+Z_7+Z_8+Z_9+Z_10+Z_11+Z_12+Z_13+Z_14+Z_15+Z_16+Z_17+Z_18;
save ('totalZvalue','TotalZ');
MeanZ=(TotalZ/.18);
save('MeanZvalue','MeanZ');

[val,ind] = min(MeanZ(:))
[I,J] = ind2sub(size(MeanZ),ind)
nplace=[I,J]
best_n=n_re(nplace(1))+1i*n_im(nplace(2))

subplot (3,3,en)
imagesc(n_im,n_re,MeanZ);

xlabel('n_re');
ylabel('n_im');
colorbar

en=en+1;
er=er+1;
end

end

function [x2]=cx2(lambda0,d,n,Cexp)
x2=(Cexp-Cteo(lambda0,d,n)).^2;
end

function [C]=Cteo(lambda0,d,n)

load('C:\Users\Weinberg\Desktop\Prueba matlab\Prueba pcolor\nSi_nSiO2\nSi_imaginary');
load('C:\Users\Weinberg\Desktop\Prueba matlab\Prueba pcolor\nSi_nSiO2\nSi_real');
load('C:\Users\Weinberg\Desktop\Prueba matlab\Prueba pcolor\nSi_nSiO2\nSi_wavelength');
load('C:\Users\Weinberg\Desktop\Prueba matlab\Prueba pcolor\nSi_nSiO2\nSiO2_real');
load('C:\Users\Weinberg\Desktop\Prueba matlab\Prueba pcolor\nSi_nSiO2\nSiO2_wavelength');

nair=1;
dSiO2=300;
nSi_1=interp1(nSi_wavelength,nSi_real,lambda0);
nSi_2=interp1(nSi_wavelength,nSi_imaginary,lambda0);
nSi=nSi_1+(1i*nSi_2);
nSiO2=interp1(nSiO2_wavelength,nSiO2_real,lambda0);

   mSiO2=Sij(nair,nSiO2)*Pj(nSiO2,dSiO2,lambda0)*Sij(nSiO2,nSi);

      mflake= Sij(nair,n)*Pj(n,d,lambda0)...
      *Sij(n,nSiO2)*Pj(nSiO2,dSiO2,lambda0)*Sij(nSiO2,nSi);

      rSiO2=abs(mSiO2(2,1)/mSiO2(1,1))^2;

      rflake=abs(mflake(2,1)/mflake(1,1))^2;

      C =(rflake-rSiO2)/(rflake+rSiO2);

end

 Most of the lines is trying to load some file or something to use in my program, but what I'm most worried about is the amount of for loops I have and how long each of those loops take. Is there a better way to approach what I'm doing without using so many for loops? I thank anyone that can help in advance.
Guillermo