Refractive Index Description
The refractive index distribution can be specified in one of two ways:

An arbitrary twodimensional refractive index profile can be uploaded as ASCII numeric values.
This profile must be uploaded as a single file using the following format:
The refractive index file must
be arranged like:
xp  xd[1]  xd[2]  xd[3]  xd[4]  ... 
yd[1]  N(x=1,y=1)  N(x=2,y=1)  N(x=3,y=1)  N(x=4,y=1)  ... 
yd[2]  N(x=1,y=2)  N(x=2,y=2)  N(x=3,y=2)  N(x=4,y=2)  ... 
..  ...  ...  ...  ...  ... 
yd[N]  N(x=1,y=N)  N(x=2,y=N)  N(x=3,y=N)  N(x=4,y=N)  ... 
where xp is the number of points along the x direction, and xd[1], xd[2] etc.. are the grid
point distances along the xaxis. yd[1], yd[2[ etc.. are the grid point
distances along the ydirection.
Click here for an example file.

The refractive index can be created using a set of builtin polygon functions. Each polygon is a
two dimenssional shape. The refractive index value inside the polygon is specified by the user, and
the refractive index outside the polygon is zero. Multiple polygons can be entered, and
most geometries of interest can be constructed this way. Click here for a complete description. The background index is assumed to be 1.0, and every polygon adds an
incremental value.