Abstract

Sapphire optical fiber application has been limited by its length, especially in blackbody optical fiber temperature sensor applications.^1-3 The new ceramic splice, made of zirconia ceramic by sintering at 1400°C, can greatly extend the fiber length. The splice material bulk has a low porosity, high strength, and works through sharp temperature cycles compare with previous works.³ The equivalent emissivity of this junction is smaller than 0.15, which make this splice a practical device. Thermal radiation from this junction is guided away from the fiber gaps with an internal alignment sleeve. By applying several splices, the length of sapphire fibers can reach several meters. In a temperature differential of 300°C between the sensor head and the splice, the sapphire fiber temperature sensor can achieve a temperature reading stability of 0.5°C at 1000°C. This technology is also applicable for other ceramic connections used in a harsh temperature environment.

© 1993 Optical Society of America