That's fine safety guidance but on the facts this is not correct.
For single and multimode fibers if it has a smaller focal spot some distance the fiber than at its tip you are talking about an assembly that includes the fiber plus an optic.
This is unambiguously true for single mode fibers. Multi mode one will diverge less
I could see there being some exception for a strange fiber which has a multi-emitter output, was nanostructured, tapered, etc..
"For single and multimode fibers if it has a smaller focal spot some distance the fiber than at its tip you are talking about an assembly that includes the fiber plus an optic."
A properly-shaped and polished fiber tip is already the optic. That's literally how it's fed into the galvo in a fiber-marking LASER. I'm also responsible for the maintenance on all equipment in the facility so I've had those machines apart more than once.
For single and multimode fibers if it has a smaller focal spot some distance the fiber than at its tip you are talking about an assembly that includes the fiber plus an optic.
This is unambiguously true for single mode fibers. Multi mode one will diverge less
I could see there being some exception for a strange fiber which has a multi-emitter output, was nanostructured, tapered, etc..