Flexible fibre bundle esp. for transmission of laser radiation - comprises multimode single fibres comprising core, sheath and protective coating

摘要

Flexible fibre bundle, for the transmission of HF radiation, esp. laser radiation, comprises multimode single fibres. The fibres comprise a core, a sheath and a protective coating of at least one layer. The crushing number R1 of the core is greater than the crushing number R2 of the sheath and the fibres are concentrated at the ends of the fibre bundle. The improvement is that for the fibres of the fibre bundle, the core dia. D1 is from 0.06 to 0.35 mm; the ratio D2/D1 of the outer dia. of the sheath D2 to the core dia. D1, is from 1.007 to 1.04; the protective coating which lies directly on the sheath has a thickness of at least eightfold the vacuum wavelength of the radiation to be transmitted, this thickness being 0.25 mm. max.; and the protective coatings on the ends of the fibres are removed to a length of 10-i00 mm, and the fibres are bonded with each other at least at the excitation end of the fibre bundle. ADVANTAGE - New fibre bundle has low excitation losses, high damage boundary values and reduced processing costs w.r.t. known fibre bundles.