matlab相干衍射成像仿真代码

### MATLAB 实现相干衍射成像仿真

在MATLAB中实现相干衍射成像仿真涉及多个方面，包括定义光源特性、计算传输函数以及应用这些函数来模拟成像过程。下面提供了一个完整的示例代码用于演示如何利用MATLAB进行相干衍射成像的仿真。

#### 主程序 `main_coherent_diffraction.m`

% Coherent Diffraction Imaging Simulation using MATLAB
clear, clc;
close all;

% Load the image and convert it to grayscale
img = imread('lenna.jpg');
img_gray = rgb2gray(img);

% Define parameters for coherent diffraction imaging
lambda = 500e-9;    % Wavelength of light (red)
diameter = 5e-4;     % Diameter of aperture
distance = 2;        % Distance from source to aperture
k_factor = 255;      % Normalization factor

% Generate Point Spread Function (PSF) based on Fraunhofer diffraction formula
psf = generate_psf(lambda, diameter, distance, size(img_gray));

% Apply PSF as a filter to simulate coherent diffraction effect
filtered_img = fftshift(ifft2(fft2(double(img_gray)) .* fft2(psf)));

% Normalize output image intensity between 0 and 255
normalized_filtered_img = uint8(mat2gray(abs(filtered_img)) * 255);

% Display original vs processed images side by side
figure;
subplot(1,2,1);
imshow(img_gray);
title('Original Image');

subplot(1,2,2);
imshow(normalized_filtered_img);
title('Coherently Diffracted Image');

此段代码展示了如何加载一幅图像并将其转换为灰度图，接着通过Fraunhofer公式生成点扩展函数（Point Spread Function, PSF），最后将该PSF应用于原始图像以模拟相干衍射的效果[^1]。

为了更精确地控制实验条件，在实际操作过程中可能还需要调整参数设置，比如改变波长`lambda`或孔径尺寸`diameter`等变量值来进行不同场景下的测试分析[^3]。