Hi jlstay,
As an application engineer at Optiwave, I’d say OptiSystem is a perfect tool for simulating Er based fiber amplifiers and ASE sources!
More seriously, we support double-cladded fibers, multimode fibers and co-doped fibers. There is also the ability to model higher order effects such as ion-ion interactions and Rayleigh scattering. These are just some of the capabilities off the top of my head. ASE generation and any type of amplification configuration are completely possible.
We also have a number of passive components such as couplers, splitters, and filters, to aid in a system design. I suggest you take a look at the tutorials/examples we have on our website at the following link:
Of course if you have any other questions (general or specific) feel free to ask me or anyone else on the forum.
Regards