If your PML is too close to a scattering object, it can cause artificial reflections. Leave at least half a wavelength of "buffer" space.
Choosing the wrong boundary kills a simulation. lumerical fdtd tutorial
Ansys Lumerical FDTD (Finite-Difference Time-Domain) is a high-performance electromagnetic simulation tool used to model the interaction of light with sub-wavelength structures. Learning to use it typically follows a structured workflow that transitions from basic geometry setup to advanced data analysis. 1. The Core Simulation Workflow If your PML is too close to a
Even experienced users fall into these traps. This Lumerical FDTD tutorial would be incomplete without troubleshooting. The Core Simulation Workflow Even experienced users fall
We will simulate a simple operating at 1550 nm.
“Run a parameter sweep,” her advisor would say, reciting another lesson from the tutorial. So she did: she varied the defect radius in minute steps. Each run mapped the peak’s frequency; a band of points formed across her plot. At a critical radius, the resonance’s Q factor shot upward—a narrow corridor where radiation loss dropped dramatically. She found it: a sweet spot predicted by theory but not obvious in earlier coarse sweeps.
Start with the Ansys blog on FDTD basics to understand the "resonance region" discretization.