D = getdata("frequencysweep","D");
f = getdata("frequencysweep","f");
lambda = c/f;

GVD_TE = -lambda^2/(2*pi*c)*pinch(D,2,1);
GVD_TM = -lambda^2/(2*pi*c)*pinch(D,2,2);
plot(c/f*1e6,GVD_TE*1e24,GVD_TM*1e24, "wavelength (microns)","GVD (ps^2/m)");
legend("TE-like","TM-like");


# create TM like material
neff = getdata("frequencysweep","neff");
neff = pinch(neff,2,2); # get neff for TM mode 

outdata = [f,real(neff),imag(neff)];

?size(outdata);
fname = "neff_TM_like.txt";
if(fileexists(fname)) { rm(fname); }

format long;
write(fname,num2str(outdata));
format short;