kelinsi.rar_ABCD系统matlab_kelinsi_matlab ABCD矩阵_光学系统_衍射 ABCD

function diffraction_cross() %规定 %0代表物平面的参数 %1代表菲涅耳解析DFFT %物函数的抽样点数 distance=input('输入观察屏到衍射屏的距离，单位mm');%=100000;%观察屏到衍射屏的距离，单位mm length=10; %衍射屏宽度，单位mm L=distance+200%单位mm A=1 lambda=0.00063;%波长，单位mm N0=N_object(length);%求解物函数的采样点的函数 N1=40/distance;%length^2/(lambda*distance);%N>= %N2=40/diatance;%length^2/(lambda*distance);%N<= %十字叉丝衍射的数值模拟 choice=0; if N0>=N1 N=N0; U=Frensel_SFFT(length,distance,lambda,N); else N=N0; U=Frensel_DFFT_S(length,distance,lambda,N) end U=abs(U); U=U.^2; U=fftshift(U); %归一化 %U=U/max(max(U)); imshow(U); subplot(1,2,1) imshow(U); title(distance) subplot(1,2,2) plot(U((N0^2/2):(N0*(N0+2)/2))); %物平面的图像 function N=N_object(length) for i=10 N=2^i; U=Object(length,N); U=fftshift(fft2(U)); U=abs(U); eps=U(N,N)/max(max(U)); if eps<10^-4 break; end end function U0=Object(length,N)%带十字叉的圆孔 U0=ones(N,N); dx=length/N; for x=1:N for y=1:N if abs((x-N/2)^2+(y-N/2)^2)>2.5^2 U0(x,y)=0; end end end %一次傅里叶变换的菲涅耳衍射积分的数值模拟 function U=Frensel_SFFT(length,distance,lambda,N) U=Object(length,N); k=2*pi/lambda; L=distance+200; A=1; for m=1:N for n=1:N U(m,n)=U(m,n)*exp(i*pi*length*length*((m-N/2)^2+(n-N/2)^2)/lambda/distance/N/N); end end U=fftshift(fft2(U)); D=distance/100-1; k=2*pi/lambda; temp=exp(i*k*L)/i*lambda*distance for m=1:N for n=1:N U(m,n)=temp*U(m,n)*exp(i*pi*lambda*distance*D/(length*length)*((m-N/2)^2+(n-N/2)^2)); end end %数值传递函数的菲涅耳衍射积分公式的数值模拟 function U=Frensel_DFFT_S(length,distance,lambda,N) U=Object(length,N);%fftshift(fft2(U)); U=fftshift(fft2(U)); L=distance+200; %dl=1/length; k=2*pi/lambda; %tenpe=exp(i*k*L) for m=1:N for n=1:N U(m,n)=exp(i*k*L)*U(m,n)*exp(-i*pi*lambda*distance/(length*length)*((m-N/2)^2+(n-N/2)^2)); end end U=fftshift(ifft2(U)); %U=fftshift(fft2(U)); dx0=length/N;%dy0=length/N; for m=1:N for n=1:N U(m,n)=U(m,n)*exp(i*pi*0.01/lambda*dx0^2*((m-N/2)^2+(n-N/2)^2)); end end