Hybrid finite-difference time-domain Fresnel modeling of microscopy imaging

Full-wave electromagnetic analysis by the finite-difference time-domain (FDTD) method is combined with the scalar diffraction method to obtain a numerical tool for optical lens imaging. The FDTD method is applied to the modeling of scattering phenomenon in the vicinity of a target. Afterward, obtained results are coupled with the Fresnel diffraction method to project an image through the lens onto the image plane. The FDTD algorithm is able to provide the solution of the electromagnetic analysis of the target with all its geometrical complexity. It is also relatively effective, since it allows the arbitrarily shaped geometry of the target to be analyzed in a specified spectrum range with only one simulation run. Such coupled FDTD-Fresnel modeling exploits the advantages of both methods, maintaining the required accuracy and speeding up the overall computation of the image.