Refractive Index Description

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

• An arbitrary two-dimensional 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 x-axis. yd[1], yd[2[ etc.. are the grid point distances along the y-direction. Click here for an example file.

• The refractive index can be created using a set of built-in 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.