Frequency sampling strategy for numerical diffraction calculations.

Diffraction calculations play an essential role in Fourier optics and computational imaging. Conventional methods only consider the calculation from the perspective of discrete computation which would either cause error or sacrifice efficiency. In this work, we provide a unified frequency response analysis from the joint physics-mathematics perspective and propose corresponding adaptive frequency sampling strategies for five popular diffraction calculation methods. With the proposed strategies, the calculation correctness is guaranteed and the calculation efficiency is improved. Such an idea of unified frequency response study would help researchers make a do-it-yourself analysis for various diffraction calculation tasks and choose or develop a method for accurate and efficient computations of the diffraction fields.