Save/load Modes objects to disk

[simbilod]

Pickling Modes currently leads to ~100MB objects on disk

What would be a best practice to save/load modes to disk?

In gdsfactory with the old femwell API I had something that saved the mesh, element, an field values, and would reconstruct the basis at runtime, which led to much smaller files (~1MB or less instead of 100)

[HelgeGehring]

There's the cached solver you can use, see https://github.com/HelgeGehring/femwell/blob/main/femwell/solver.py#L145
It only caches the actual call to the solver, nothing more.

There's still some calculations afterwards for normalizing the field. So it might be not saving enough time.

Maybe give it a try and then we can see if we add something!