Long fiber Bragg gratings for liquid level sensing

Autores UPV
Año
CONGRESO Long fiber Bragg gratings for liquid level sensing

Abstract

The study, design and performance evaluation of fiber Bragg grating (FBG)-based photonic sensors to the aim of realizing devices for discriminating both liquid level and temperature changes are proposed and experimentally performed. The analysis carried out is based on a 10 cm-long uniform FBG specially designed for this particular aim. Two different techniques have been implemented. The first scheme presents a time-frequency analysis by using a short optical pulse. Here, the back-reflected signal has been monitored and a 2 mm spatial resolution is achieved, determined by half the incident pulse duration. Second, a technique based on microwave photonics (MWP) filters has been demonstrated, too. Here, a spatial accuracy under 0.5 mm is obtained using a modulator and a photo-detector with a modest bandwidth of less than 1 GHz. Furthermore, in both configurations the temperature of the liquid is detected.