How to plot solutions for different values of parameters on same file?

How to plot solutions for different values of parameters on same file i..e,

close all;

X=-5:.1:5;

T=-5:.1:5;

%i=1;

w0=.5;

%h=3;

eta=(1./2);

sig=-1;

e0=2*w0*sqrt(eta-sig);

mu1=.5*1i;

[x,t]=meshgrid(X,T);

%a=4*mu1.^2-(w0.^2./2);

A=(1./(-2*w0.^2+2*mu1.^2)*sqrt(e0.^2-4*mu1.^2).*((-2*w0.^2+2*mu1.^2)*x+t));

a=e0*sinh(A)-2*1i*mu1;

b=e0+2*1i*mu1*sinh(A);

r1=e0-4*1i*mu1*(a./b);

surf(x,t,abs(r1));

shading flat;

grid off;

How to plot 'r1' for different values of 'mu1' on same figure like this