comparesemianalysis_discrete_fft_1d.m

通过计算晶体结构来确定其光谱分布

%CompareSemiAnalysis_Discrete_1D.m
%Ref:Linfang Shen, Sailing He, and Sanshui Xiao, Large absolute band gaps
%in two-dimensional photonic crystals formed by large dielectric pixels,
%Physical Review B 66, 165315-1->-6 (2002)
clear;
clear global;
close all;

cnh=100;                  %Half number of pixels in one cell
pw=1;                   %Width of pixel
cn=2*cnh;               %Number of pixles in one cell
cw=cn*pw;               %Width of cell
cwh=cnh*pw;             %Half width of cell

HN=cwh;              
%Half number of Fourier coefficients
N=cw;
%Total number of Fourier coefficients

fx=(-HN:HN-1);
fxh=1:HN;
%ebxn=rand(1,cwh);         %One fourth of a cell
T=cw/20
ebxn=1+cos(2*pi*fxh/T)
ebxn_1=cat(2,ebxn,fliplr(ebxn))
tN=max(size(ebxn_1))

hN=0;
hN=hN+1;
figure(hN);
plot(fx,ebxn_1);
title('Original data');

FS=zeros(1,N);
for n=-HN:HN-1
    FS(HN+n+1)=SquarePixel_ebxn_1D_FC(ebxn,pw,n);
end
hN=hN+1;
figure(hN);
subplot(2,2,1);
plot(fx,real(FS));
title('Real A');
subplot(2,2,2);
plot(fx,imag(FS));
title('Imagery A');

ebxn_1=cat(2,ebxn,fliplr(ebxn));
tN=max(size(ebxn_1));

FS_1=fft(ebxn_1)/cn;
FS_2=FS_1;
z_cn=find(abs(FS_2)<1.0e-10);
FS_2(z_cn)=zeros(1,length(z_cn));
FS_1=fftshift(FS_2);

subplot(2,2,3);
plot(fx,real(FS_1));
title('Real B');
subplot(2,2,4);
plot(fx,imag(FS_1));
title('Imagery B');

disp('CompareSemiAnalysis_Discrete_1D ends');