Assuming there is no segment/length limitations, or at least the same as in regular fibers:

A tracing line along under-sea cables and pipes – a tracing line integrated to the housing of the undersea cable can give precise mapping of the cable, which could also act as a line measurement for the profile of the sea floor.

As well as running these inside oil pipelines. Coupled with other sensors/data – can give extremely precise locations for cuts, breaches in line or pipe.

With an alerting threshold it can confirm compliance with bend radius requirements for a lot of things, as well as perhaps be able to measure tension applied to lines used for various rigging.

it would be interesting to see it spiraled around a pipe/tube in a helix/double-helix to give an even better full measurement of the bends/tensions/ orientations of the objects its measuring.

very short one on hinges could potentially very cheaply detect any state of being ajar.

Put into gloves – it could be the easiest way to translate the movements of a human hand to the movement of a mechanical hand – such that if you’re wearing a glove that controls the hand of a mech – you could potentially have precision same as your physical digits. Coupled with haptics – it could make driving huge mech hands very sensitive and dexterous.

woven into fabrics, it could be placed into the soles of athletic shoes and precisely monitor how the foot is working in all aspects of running walking etc – then this can be mapped to algos to better mimic the human foot to a robot foot.

woven into fishing-trawler-nets could be used to acurately map the ocean floor where trawling occures.

sandwiched into carbon fiber layers used in, say, spacecraft designs could provide hull/skin integrity measurements with minimal cost/weight. If there is a deformation in a hull or skin of a craft – it could pinpoint exactly where the deformations are happening – or a hole/crack has appeared.

In a body suit – it could relieve the need for visual mocap – and you could have it in both athelete/soldier/whatever to have a full detail of the physcial position of a remote person you are tracking such that you could get the full spatial positioning of a team as they go through a place you cant have visual of them

As well as recording human movements to have humanoid robots learn the movements easily.

lining aircraft wings could continuously measure flex/fatigue of an airframe and give a better long-term lifecycle of the stresses on the metals – or more accurately measure the overall stresses in certain high-performansce maneuvers to give realtime feedback on the stresses imposed by various actions for more refined flight control.

Basically if you can integrate into certain domains – it could be the same as adding a layer of “fluid/aero dynamics” to a real object in real time.

The list can go on.

It would be best to see how thin and tightly woven you can make these…

I have many more applications… but the above are all fairly obvious ones.

I would love to catch up!

Best, Tim Reha

https://en.wikipedia.org/wiki/Optical_time-domain_reflectometer