Abstract: When the phase of Fresnel diffraction is calculated by Fourier transform algorithm, the phase distribution curve of the receiving surface will be hopping when the phase is wrapped, and if it is unwrapped, it will inevitably lead to the wrong result. The reason that the phase jump on the receiving surface is caused by the Fourier transform algorithm is analyzed. It is because the FFT’s way of indexing the matrix is different from that of the DFT, which leads to the difference between the phase and the real phase of the calculated result. The phase jump can be corrected by doing fftshift respectively before and after the FFT operation. The Fresnel diffraction integral of the two-dimensional moment holes is simulated by using a single FFT, and the phase jump of the receiving surface is corrected by using two times cepstrum, which proves the feasibility of the proposed method.

Key words: Fresnel diffraction, phase jump, Fourier transform algorithm, cepstrum, simulation