Fig. 1. 2D and 1D distributions of rectangular aperture diffraction field obtained by different algorithms. (a) Single Fourier transform Fresnel diffraction method; (b) original angle spectrum method; (c) zero-padding angular spectrum method

Fig. 2. Wave propagation principle of band-limited angular spectrum method and diffraction filed distributions of rectangular aperture. (a) Schematic diagram of wave propagation; (b) 2D and 1D distributions of rectangular aperture diffraction field obtained by band-limited angular spectrum method

Fig. 3. 2D and 1D distributions of diffraction field at the focus point for telephoto lenses obtained by different angular spectrum methods. (a) Band-limited angular spectrum method; (b) scaling angular spectrum method

Fig. 4. Schematic diagram of scaling angular spectrum calculation and diffraction field distributions obtained by band-limited scaling angular spectrum method. (a) Schematic diagram of scaling angular spectrum calculation; (b) 2D and 1D distributions of diffraction field at the focus point for telephoto lenses obtained by band-limited scaling angular spectrum method

Fig. 5. 2D and 1D distributions of diffraction field for the large-size circular axicon lenses obtained by different angular spectrum methods. (a) Band-limited angular spectrum method; (b) scaling angular spectrum method; (c) band-limited scaling angular spectrum method

Fig. 6. DOE beam shaping system and top-hat beams obtained by different methods. (a) Schematic diagram of the phase distribution and top-hat beam output of a large-size DOE; (b) intensity and phase distribution of the DOE diffraction field obtained by band-limited angular spectrum method; (c) intensity and phase distribution of the DOE diffraction field obtained by scaling angular spectrum method; (d) intensity and phase distribution of the DOE diffraction field obtained by band-limited scaling angular spectrum method