Visualization routines

[smartalecH]

It might be nice to add some visualization routines. In theory, this should be really straightforward, especially since everything is defined later by layer. But there are many ways one could envision an API for this (especially since FMMAX is fundamentally so low-level).

So here are a few use cases where visualization is really important. Maybe by outlining these, we can sort out a reasonable API:

• We want to ensure the layer stack is in the right order with the right absolute thicknesses, and that each layer has the right material.
• When defining something with curvature (like a uLens) we want to make sure the curvature is properly discretized in the layered direction
• We want to make sure that free-form structures (e.g. for TO) are properly inserted into the system, so full cross sections of arbitrary slices would be useful.
• We don't want to have to simulate anything to visualize things, so we prefer not to work with LayerSolveResult objects (or scattering matrices etc)

[mfschubert]

It would be nice to sketch out a "workflow" that involves all of these steps, to help inform what is developed. Let's discuss during our next developer's meeting.

[smartalecH]

One thing we should do, is survey and establish the most popular API for FMM/RCWA tools, and essentially "clone it," that way we can maximize traction and engagement.

Then, we should see if we can generalize it to more applications (which FMMAX was hoping to address).