Ansys Insight : Using the non-uniform mesh (periodic structures)
The non-uniform mesh generation does not necessarily produce meshes that automatically match the periodicity of the physical structure. In some cases, such as high Q photonic crystal micro-cavities, using a mesh that has the same periodicity as the physical structure being simulated is better for numerical accuracy. In this case, a mesh override region can be used to ensure that a/Δ=N
where a is the period, Δ is the mesh cell size and N is an integer.
To insert mesh override regions, select the Mesh option of the Simulation button.
The mesh override regions allows you to set dx, dy and dz over a particular region. For example, if you have a triangular lattice PC in the x-y plane, with a lattice constant of 1 micron. You could use the following settings for a mesh override regions that covers the entire simulation region in x and y. Note that dx = 1/20 microns, while dy = sqrt(3)/2/20 microns. The simulation region has an x-span of 10 microns and a y span of 10*sqrt(3)/2 microns.
By choosing to not use "override z mesh", the default non-uniform mesh in the z-direction will be generated.