title: Calculation of the volumetric diffracted field with a three-dimensional convolution: the three-dimensional angular spectrum method.
abstract: The first Rayleigh-Sommerfeld diffraction formula is treated in an exact form as a three-dimensional (3D) convolution in the spatial domain. Therefore, a 3D Fourier transform can be employed to convert the 3D diffracted electromagnetic field to the reciprocal space without approximations, which we call the 3D angular spectrum (3D-AS) method. It is also demonstrated that if evanescent waves are neglected, the 3D-AS method can be readily implemented numerically, with the results in good agreement with theoretical predictions.
authors: Shan Shan
authors: SS
authors: Kou
authors: Colin J R
authors: CJ
authors: Sheppard
authors: Jiao
authors: J
authors: Lin