Lizzie, the third combo box in the User Defined Function dialog box has a list of global variables that could be changed during a scan calculation. However, I can’t guess where you are going with this picture…
I would like to make a comment on your comment of December 2nd. Here you say “The scanning width equal to 1 means the original width of cladding is not shrunk or expanded.” The interpretation of “width” as a factor instead of a physical distance is indeed used in some places in Optiwave software. However, in this context the width means the physical distance in microns, it is not interpreted as a factor. The value of modal index of LP(0,2) you get when width = 1 is for a fibre with a cladding width of 1 micron. The cladding width is not 1 * original width.
I hope that makes sense and clears up the confusion!