How long will fiber optics last?

In case of glass basically indefinitely the inert characteristics of the material. It refers to the actual fiber, but not to the polymer cladding. Also the ordinary ends being an encapsulation of epoxies will behave less predictably and execute erratically, depending of several factors, as level of radiation exposure and temperature of operation.

As far as polymer systems are involved 20 years for the conductors is the standard guarantee into the industry. It also refers to the actual fiber, without reference to the ordinary end whose average life depends upon similar factors outlined before.