Navigating SPINS Codebase

SPINS is a large nanophotonic optimization library with several different structures. Here we provide a brief overview of the sublibraries in SPINS:

• invdes: This is the initially-released library that handles the inverse design aspect of SPINS.
• goos: This is the next generation inverse design library meant to replace the older invdes library. This library is still under development, though you can run many optimizations already with goos.
• goos_sim: This module contains simulators for goos.
• fdfd_tools and fdfd_solvers: This sublibraries handle setup and running finite-difference frequency-domain (FDFD) simulations.
• gridlock: This library handles drawing on the Yee grid. The Yee grid is a set of offset grids that are used in FDTD and FDFD simulations.

There are a few other small sub-libraries under the spins package that perform tasks specific for the invdes library, which we will ignore here.