Optical fibre prodn. with polymer core and plastics sheath - by polymerising monomer mixt. in situ in shrink fit tube with specified properties

摘要

Prodn. of optical fibres with a polymer fibre core and plastics sheath is carried out by filling the core with the monomer mixt. for the core and polymerisation in situ. The sheath consists of a shrink-fit tube with a refractive index at least 1% less than that of the core, a shrinkage temp. in the 80-350 deg.C. range, deg. of shrinkage of 1:(1.2-5) and internal surface roughness less than 1200 microns. The sheath pref. has a shrinkage temp. 100-200 deg.C., deg. of shrinkage of 1:(2-4) and internal surface roughness of under 200 microns. Its dia. is 0.1-50mm and wall thickness at least one multiple of the wavelength of the light concerned. The monomer mixt. gives a thermoset core. ADVANTAGE - High quality optical fibres resistant to thermal distortion can be produced easily, even on the technical scale.