Fabry-Perot cavity based on silica tube for strain sensing at high temperatures

Abstract

In this work, a Fabry-Perot cavity based on a new silica tube design is proposed. The tube presents a cladding with a thickness of similar to 14 mu m and a hollow core. The presence of four small rods, of similar to 20 mu m diameter each, placed in diametrically opposite positions ensure the mechanical stability of the tube. The cavity, formed by splicing a section of the silica tube between two sections of single mode fiber, is characterized in strain and temperature (from room temperature to 900 degrees C). When the sensor is exposed to high temperatures, there is a change in the response to strain. The influence of the thermal annealing is investigated in order to improve the sensing head performance. (C)2015 Optical Society of America