Optical properties of diamond-like cladding for optical fibres

Abstract

This article presents a novel application of DLC layers: cladding material for silica optical fibre's core. The coats were successfully obtained using the radio frequency plasma chemical vapour deposition (RF PCVD) method. A technological subject of depositing diamond-like carbon layers onto dielectric substrates is also raised. An original way of placing samples in a plasma reactor and a process taken in order to get a desirable effect were worked out. Different values of optical fibre transmission, which depend on the RF PCVD process parameters, can be observed. Obtained coats can be characterized by good adhesion and stability. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images of the deposited DLC layer were made. A partly uncoated optical fibre, covered by the DLC layer, can act as a sensing head. The experiments prove very high sensitivity to humidity depending on a length of the uncoated section and deposition process parameters.