m.m

二元傅立叶全息图在matlab上的实现。体现了其五个实现步骤。结果为生成啁啾光纤光栅。

clear;
N=1800;
y=linspace(-10.8,10.8,N);
fy=0.5*(1+cos(11.8372*y));
A=fy
B=ones(38,1);
C=B*A;
figure;
imshow(C);
a=fft2(C,38,180);
b=fftshift(a);
figure;
imshow(b);
A1=abs(b);
B1=angle(b);
Amax=max(max(A1));
A2=A1/Amax;
B2=B1/(2*pi);
m=10/38;
n=21.6/180;
W=m/2;
figure;
axis([0 10 0 21.6]);
hold on;
for J=1:38
    x0=m/2+(J-1)*m;
    for I=1:180
        y0=n/2+(I-1)*n;
        H=A2(J,I)*n;
        F=B2(J,I)*m;
        if abs(F)<=m/4
            x2=x0-W/2;x3=x0+W/2;
            y2=y0-H/2;y3=y0+H/2;
            fill([x2,x2,x3,x3],[y2,y3,y3,y2],'k');
        elseif F>m/4
            x22=x0+F-W/2;x33=x0+m/2;
            y22=y0-H/2;y33=y0+H/2;
            fill([x22,x22,x33,x33],[y22,y33,y33,y22],'k');
            x222=x0-m/2;x333=x0+F+W/2-m;
            fill([x222,x222,x333,x333],[y22,y33,y33,y22],'k');
        else x22=x0-m/2;x33=x0+F+W/2;
            y2=y0-H/2;y3=y0+H/2;
            fill([x22,x22,x33,x33],[y2,y3,y3,y2],'k');
            x222=x0+F-W/2+m;x333=x0+m/2;
            fill([x222,x222,x333,x333],[y2,y3,y3,y2],'k');
        end
    end
end
axis('equal');
axis off;