[gsnedders]

That looks like single mode fiber never refracts… Surely it can't go round any bend, then, though? (And I'm probably missing something obvious. It's been a while since I've done optics of any sort.)

[amazon_not]

> That looks like single mode fiber never refracts…

No, it does.

> Surely it can't go round any bend, then, though?

No, if you bend the fiber too much the light leaks out into the cladding.

[rocqua]

I believe the fiber acts as a waveguide, essentially keeping the wavefront perpendicular to the fiber at all times.