一组干涉光信号,用FFT求得由什么频率的光组成,还有每种光的强度
论文《Ultrasensitive refractive index sensor based on enhanced Vernier effect through cascaded fiber core-offset pairs》
论文《High-temperature sensor based on suspended-core microstructured optical fiber 》
一组干涉光信号,用FFT求得由什么频率的光组成,还有每种光的强度
论文《Ultrasensitive refractive index sensor based on enhanced Vernier effect through cascaded fiber core-offset pairs》
论文《High-temperature sensor based on suspended-core microstructured optical fiber 》
clc;
clear;
close all;
lambda1 = 500e-9;%500nm光
lambda2 = 600e-9;%600nm光
c = 3e8;%光速
w1 = c/lambda1;%500nm光频率
w2 = c/lambda2;%600nm光频率
time = 1e-13;%时间长度100fs
sample_fre = 2*(w1+w2);%采样频率,至少是2*max(w1,w2),奈奎斯特采样定律
sample_interval = 1/sample_fre;%采样间隔(s)
t = 0:sample_interval:time-sample_interval;
E1 = 10*exp(1i*2*pi*w1*t);%光场1
E2 = 20*exp(1i*2*pi*w2*t);%光场2
E = E1+E2;%干涉
F = fftshift(fft2(E))*sample_interval/time;%傅里叶变换,将零频移动至中央
ft = -sample_fre/2:1/time:sample_fre/2-1/time;%频域坐标
figure
subplot(221);plot(t,real(E1));xlabel('时间(s)');ylabel('振幅');title('光场1');
subplot(222);plot(t,real(E2));xlabel('时间(s)');ylabel('振幅');title('光场2');
subplot(223);plot(t,real(E));xlabel('时间(s)');ylabel('振幅');title('干涉场');
subplot(224);plot(ft,abs(F));xlabel('频率(Hz)');ylabel('强度');title('频谱');
你可以看一下这个代码