  Inverse design through optimization of dielectric photonic devices is a very
powerful tool. However so far the direct solver used in the design process is
almost always restricted to solve Maxwell's equation in two dimensions (2D).
Here we will show that by using a specific three dimensional (3D)
electromagnetic field-solver we can implement a full 3D inverse design tool for
Silicon On Insulator (SOI) slab based photonic structures which can be run on a
normal desktop computer.
