I would actually create a fiber spool the same way I would create a wire spool but with extra attention to the minimal bend radius. I usually don't spend much on bend radius but with fiber it's important so you don't snap your fiber.
You can define fiber the same way you'd define any other wire or cable spool. Depending upon your fiber and your tolerance for attenuation, bend radius may not be that much of an issue.
Back in the early 2000's the minimum bend radius for the best fiber was still only about 30mm... today you can almost tie fiber in a knot without hurting it. Be aware though, if you choose to set your minimum bend radius using the spool settings in Creo Cabling, you may not always get the results you expect. Sometimes a cable will refuse to route even though there's technically sufficient room to achieve routing without violating the minimum bend radius.
This is just something to look out for... I think I'm straying from your original question though so I'll stop here!