Optical fiber cable which resists damage caused by a hostile environment

Abstract

A hermetically sealed optical fiber cable (20) includes a core (21) comprising a plurality of optical fiber ribbons (22,22) disposed within a core tube (30) comprised of a high temperature resistant polymeric material. The core tube is disposed within a hermetic sealing member (40) which comprises a metal of low electrochemical activity having a sealed seam. An outer jacket (50) is disposed about the hermetic sealing member. The core may be filled with a waterblocking filling material (35). The material of the core tube undergoes only limited degradation because of the limited amount of oxygen and/or moisture trapped in the hermetically sealed cable. The filling material and/or other materials of the cable scavenge moisture and oxygen which travel longitudinally of the cable and reach portions of the cable subjected to a high temperature because of a leak in an adjacent steam line. The filling material and/or other materials are such that they cooperate with polymeric materials of the cable to prevent oxygen and humidity from degrading coating material of the optical fiber. Further, the filling material and the core tube are such that degradation of the core tube in the hermetically sealed cable is avoided.