In the Export Profile… / Import Profile feature, the profile data is arranged as a sequence of concentric layers of specified width and refractive index. The first column has the widths (annuli) in microns. The second column has the refractive index found in each layer (annulus). The first column is not a coordinate value of the radius. For example, a step index fibre with core diameter 8.3 and cladding outer diameter 125 µm will appear as
BCF2DPC
2
4.15 1.452
58.35 1.447
and not as it would be in coordinate form
BCF2DPC
2
4.15 1.452
62.5 1.447
If the data is presented in coordinate form, the radii will be interpreted as widths and the fibre will appear somewhat larger than expected!