Coated optical fibre.

摘要

A coated, embrittlement-resistant optical fibre thermometer fibre is disclosed, which can be a sapphire or silica fibre with a metallic coating which prevents the fibre from becoming brittle at high temperature, and enhances transmission of radiation through the fibre. The coating can be applied over a thin "conductive" film attached to the fibre exterior using vacuum metallisation, sputtering, or organo-metallic deposition. The coating may comprise pure platinum electroplated over a thin conductive film. The fibre may include a first end terminating in a blackbody radiator in a furnace and a second end terminating at a receptor apparatus. A coated fibre of the present invention provides a hermetic seal around the fibre to prevent its exposure to hydroxyl ions in the atmosphere. Fibres of the invention will remain fexible even after exposure to temperatures well over 1000 DEG C. The coating also prevents unwanted external radiation from entering the fibre.