F₂-laser ablation of Fabry–Perot cavities in optical fibres: chemical sensors

Abstract

The authors have previously reported on the micro-machining of intrinsic fibre Fabry–Perot cavities in fused silica optical fibres using a 157 nm excimer laser. The current paper reports on a technique for estimating the depth of the cavity by measuring the transmitted light intensity during the micro-machining of optical fibres using a 157 nm laser. Single and multiple cavities were created in silica and sapphire optical fibres and the feasibility of using micro-machined cavities for monitoring chemicals is demonstrated.

Process monitoring of fibre reinforced composites using a multi-measurand fibre-optic sensor

“…Therefore, for refractive index-based process monitoring, it is necessary to monitor the temperature. Optical fibre-based sensor systems for monitoring the refractive index include core/cladding interactions where the matrix acts as cladding [4,5], reflections emanating from cleaved optical fibres immersed in the resin [3], cavities in optical fibres [6] and long-period gratings [7].…”