Innovative Hybrid Materials for Coating Special Silica Optical Fibers

Inorganic organic (hybrid) materials (ORMOCER®s ) were used to coat optical fibers for use in Fiber Bragg Grating sensors and in high power transmission fibers. The materials are synthesized via sol-gel method and are equipped with reactive acrylic groups enabling UV-curing in a combined fiber drawing and coating process as well as with special functional and fluorinated groups allowing the adjustment of the refractive index. The coatings synthesized show a high peak thermal stability > 300 °C and maintain the high tensile strength of 5.54 GPa with a Weibull parameter of 182 after thermal cycling up to 300 °C. In addition, low refractive index (n) ORMOCER® coatings were developed with n=1.38 and corresponding attenuation of a coated silica fiber of 18 dB/km. Based on the new applied pressure coating technology the coating material consumption was significantly decreased.