Dp. Dowling et al., APPLICATION OF DIAMOND-LIKE CARBON-FILMS AS HERMETIC COATINGS ON OPTICAL FIBERS, DIAMOND AND RELATED MATERIALS, 5(3-5), 1996, pp. 492-495
The application of diamond-like carbon (DLC) films as hermetic coating
s on optical fibres was investigated. Films with refractive indices in
the range 1.7-2.0 (at lambda = 675 nm) were deposited at pressures up
to 5 Torr. The hermeticity of the coatings was determined using water
penetration studies monitored using a combination of spectroscopic el
lipsometry and atomic force microscopy. The resistance to moisture pen
etration was found to be better for higher refractive index rims. The
coatings were applied to optical fibres in a continuous in-line system
as the fibre was drawn. Coatings of thicknesses in the range of 10-30
nm were achieved on quartz fibres with outer diameters of 200-1000 mu
m at fibre drawing speeds of up to 3 m min(-1).