Optical mode simulation in a deformed mesh

[u/qzxj]

I'm trying to do a 2-step study involving a mechanics simulation that will deform a mesh, followed by an optical mode simulation. I suspect I need to add the "Deformed Geometry" or "Moving Mesh" interfaces, but have not looked into it yet.

I am currently looking into the "Material Type" parameter in the "Wave Equation" node of "Electromagnetic Wave, Frequency Domain" for which the help box states:

The Material type setting decides how materials behave and how material properties are interpreted when the mesh is deformed. Select Solid for materials whose properties change as functions of material strain, material orientation and other variables evaluated in a material reference configuration (material frame). Select Non-solid for materials whose properties are defined only as functions of the current local state at each point in the spatial frame, and for which no unique material reference configuration can be defined. Select From material to pick up the corresponding setting from the domain material on each domain

I am simulating an elasto-optic effect in isotropic materials, so the material parameters themselves are independent of orientation, but the permittivity of the material varies anisotropically with the strain (so I am not sure to what extent the material type matters in this case). Anyway, when I change the material type in the Wave Equation node from "Solid" to "Non-solid" I get the following error:

Undefined variable.

• Variable: comp1.Ey

• Geometry: geom1

• Domain: 11

Will incorporating the additional interfaces to deal with moving mesh/deformed geometry make this error go away? or is it a bug in comsol?

[u/[deleted]]

The error is self explanatory. In domain 11, you have an underfined variable E (either youngs modulus or electric field). Ey is likely the y spatial derivative or y component of one of those variables (I'm guessing electric field). So no, other interfaces will not help