Zhang Wenhui, Zhang Hao, Jin Guofan
Opt Lett. 2020 Mar 15;45(6):1543-1546. doi: 10.1364/OL.385553.
The band-extended angular spectrum method (ASM) is proposed in this Letter for both near- and far-field diffraction calculation with high accuracy. Due to the aliasing problem of the transfer function (TF), the ASM is not suitable for far-field diffraction calculation. For band-limited ASM, the non-aliased bandwidth of the TF would shrink rapidly with the increase of the propagation distance, which would reduce the calculation accuracy in the far field. For the proposed band-extended ASM, the non-aliased bandwidth is significantly extended by rearranging the sampling points in the spatial frequency domain. Therefore, more frequency components of the TF contribute to the wave-field calculation, leading to a much wider propagation range and a higher computational accuracy.
本文提出了带扩展角谱方法（ASM），用于高精度的近场和远场衍射计算。由于传递函数（TF）的混叠问题，ASM不适用于远场衍射计算。对于带限ASM，TF的无混叠带宽会随着传播距离的增加而迅速缩小，这会降低远场的计算精度。对于所提出的带扩展ASM，通过在空间频域中重新排列采样点，无混叠带宽得到了显著扩展。因此，TF的更多频率分量有助于波场计算，从而实现更宽的传播范围和更高的计算精度。
