FDTD 101: Introduction to subpixel averaging
Lecture 10: Introduction to subpixel averaging
In this lecture, we discuss a powerful method known as subpixel averaging that enables the FDTD algorithm to capture geometric features below the discretization level. We discuss the basic ideas as well as some subtleties associated with subpixel averaging.
- Take the simulation of the slab transmission spectrum in 1D as an example, show the simplest scheme of subpixel averaging: spatial average of the dielectric function within each unit cell. The permittivity assignment over the Yee-grid will vary even for a small change of the slab thickness below the grid size.
- Show the derivation of the subpixel averaging formula based on Ampere’s law for the tangential component of the electric field that is parallel to the interface.