Composite insulators with built-in optical fibre, and methods of making them.

摘要

An optical fiber built-in type composite insulator is provided having a sealing portion (4) in a central axial hole (2) of the insulator for sealing the optical fiber (3). The sealing portions (4) are made of inorganic glass arranged at both ends of the hole (2) for sealing the optical fiber (3) therein. Axially recessed portions (10) e.g. annular grooves are arranged around the ends of the hole, and heat generating elements (6) arranged in the recessed portions (10) for heating and melting the inorganic glass to form the sealing portions (4) at both ends. <IMAGE>