Hi Ricardo,
You can import the fiber profile from a file, e.g. listing radii-indices of each region. For custom grating profiles, however, the ‘user defined function’ option provides ultimate flexibility in defining the profile. You can simply define the shape function and possibly use the built-in scripting capability (similar to Basic, e.g. IF THEN ELSE etc.) to define desired shape function over the grating period. The function editing area comes with quick access (click & place from combo boxes) to global variables (x:the position variable varying from 0 to grating period, Period:grating period etc.), math functions and constants. You can readily run/debug the function and visualize the grating profile graphically with designing your profile. For complete list of capabilities and scripting commands please see Appendix A of the Manual.
You should be able to define a square profile with custom duty cycle through a conditional block using global ‘x’ and ‘Period’ variables.
Kind regards,
Amin