Electrolytic Joints Between Metal Surfaces and Metal-Coated Fibers for Application in High Temperature Optical Fiber Sensors

In this study, an innovative method is presented for preparing optical fibers for application in fiber optic sensors operating in harsh environments. It is shown, how to attach a metal-coated fiber electrolytically to a metal sensing element, as well as an electroless method for depositing a nickel protective layer on optical fibers. Additionally, the results of the reliability tests of these methods are presented. It is also shown, that by depositing an additional nickel protective layer, it is possible to slow down the oxidation process of the copper coating. Analysis of the conducted experiments allows us to predict, that the connection method investigated and the method of protecting the fiber are robust and may find application in industrial optical sensors.