Fibre optic cables are generally not armoured. They are basically very long glass rods inside rubbery plastic sleeves. There is probably something else between the glass and the outer sleeve to help avoid stress on the glass bit when flexed. You run them through conduit.
When run over a really long distance then you would obviously run them through a SWA type cable. That is generally a submarine cable.
My office (UK) has several private telegraph poles - three of them. It's simply an oddity of being a bit odd - the building that is! It used to be a NHS clinic and for ... reasons ... each desk had its own BT exchange line. They didn't seem to have an exchange (PBX) nor use the one in the hospital that is about 200m away. There is a 150 pair line running to the building. It took two days to strip out the redundant wiring inside and out when we bought the place. We have a IP PBX.
We bought a couple of leased lines and a pole was erected by OpenReach to carry them, instead of using the existing wood work. The fibres look like a four or eight pair of which two are in use. They are quite thin, rn through some trees and have survived some pretty windy weather so far, so all good.