Extracting Field Information Embedded Within a Coarse Pseudospectral Time-Domain Simulation

With a coarse simulation grid, the pseudospectral time-domain (PSTD) simulation technique is advantageous to model macroscopic electromagnetic problems or optics problems. Due to the coarse grid appearance, the high accuracy and fine details of the field distribution in a PSTD simulation are often overlooked and underestimated. Here, we propose a numerical technique to harness the embedded field information as dictated by the Nyquist limit. Simulation results show that the proposed densification technique can be applied to 1-D, 2-D, or 3-D PSTD simulations and reconstruct the coarse grid into a high-resolution field distribution, revealing fine field variations that were not visible before.