Hello, I am using MATLAB to simulate a Fraunhofer diffraction pattern for a given aperture, but I have a little question. Hope someone can help. Sorry I am just a high school student and does not completely understand all mathematic deductions about Fraunhofer Diffraction on Wikipedia. I simply learn the way to generate the diffraction pattern: use a matrix of 0 and 1 to describe the aperture, take the Fast Fourier Transform of the matrix, "fftshift" it, display the transformed image to an image, and I get the diffraction. I made programs for 1-dimensional and 2-dimensional apertures, and the diffraction looks well. But it seems that the diffraction pattern simulated in this way is independent of the frequency (or wavelength) of the incident light. i.e., as long as I get an aperture, I get an only diffraction pattern regardless of the wavelength of the light, because there are no light properties described in my program. In reality that is not the case: for example the wavelength of light determines the distance between two fringes in the double-slit diffraction; for the same double-slit, the shorter the wavelength, the finer the fringes of diffraction pattern. Well, how can I put wavelength into consideration when I simulate the diffraction? Thanks.