In OptiFiber, after creating your desired fiber profile go to the File menu and choose “Export Profile…”. When you save the file make sure that you choose the .dat file type. You can open this file up in a text editor to see the file structure.
Then in OptiSystem just browse to where you saved the .dat file and choose it. If the .dat file does not show up either rename the file to .txt or choose to browse “All Files (*.*)” in the browser.
Regards