Multipoint Fibre Optic Refractive Index Sensors

Abstract

We propose a multisensor network where the refractive index modulators are distributed in cascade along the optical fibre. Reflections at fibre glass-monitoring medium interfaces provide a train of time multiplexed pulses. Backscattered radiation in the fibre serves as a reference channel for the individual sensors which can be designed for temperature. pressure, chemical composition measurements. AbstractWe propose a multisensor network where the refractive index modulators are distributed in cascade along the optical fibre. Reflections at fibre glass-monitoring medium interfaces provide a train of time multiplexed pulses. Backscattered radiation in the fibre serves as a reference channel for the individual sensors which can be designed for temperature, pressure, chemical composition measurements.

Distributed and Multiplexed Fiber Optic Sensors

“…As the effective reflectance of each element is sensitive to displacement of the retroreflective surface, temperature, pressure, force, and so on may be sensed via suitable transduction means. Figure 11.9b shows another reflective sensor concept, based on the change in Fresnel reflectance at a normal interface between the fiber and an external medium of variable (i.e., temperature-dependent) refractive index [26]. In this configuration, the receiving fiber is angled so as to avoid unwanted multiple reflections between the two fiber end faces.…”

“…26 Topologies for frequency-division multiplexing of interferometric sensors.11.4 INTERFEROMETRIC SENSOR MULTIPLEXING…”