This video is taken from the DGTD Learning Track on Ansys Innovation Courses.
In this unit we will learn about applications where using the DGTD as an optical solver
has an advantage over other optical solvers such as FDTD.
First, in applications where there is a possibility to have discontinuous fields across an interface
between two materials DGTD can provide highly accurate results.
This is due to the fact that DGTD method can handle discontinuous fields at material interfaces
Discontinuous fields usually appear at metal/dielectric interfaces which often involves plasmonic
structures and metamaterials.
In addition, since the DGTD method uses an unstructured mesh grid, it can more accurately
model non-axis aligned structures with arbitrary geometries.
For example, you can see here that when modeling an sphere by a solver such as FDTD which uses
a rectilinear mesh grid, the sphere suffers from what is called as staircasing effect
due to its curvature which can reduce the accuracy of the simulation.
On the other hand, an unstructured mesh can more accurately represent the curvature of
the sphere and therefore offers a more accurate simulation.
There are some applications where DGTD might not offer any advantage over FDTD regarding
the speed or accuracy of the simulation but users might still prefer to use DGTD due to
the Multiphysics capabilities offered by the DEVICE environment.
These cases include a combination of optical and thermal simulations or optical and electrical
This will save the user the extra effort required to transfer simulation data between DEVICE
and FDTD Solutions when performing a Multiphysics simulation.
In the next unit, we will review some application examples in Lumerical’s knowledge base that
use the DGTD solver.