A Fiber-Optic Sensor for Simultaneous Temperature and Pressure Measurements Based on a Fabry–Perot Interferometer and a Fiber Bragg Grating

Abstract

This paper presents a sensor for simultaneous pressure and temperature measurements, which is made entirely of quartz components and uses a Fabry–Perot interferometer and a fiber Bragg grating (FBG). This combination allows simultaneous temperature and pressure measurements, as well as the reduction of the contribution of temperature to the pressure measurement. The sensitive element is a quartz-glass membrane manufactured by etching. The sensitivity of the sensor to the pressure is 50 nm/bar; the sensitivity to the temperature is 4.6 nm/°C on the Fabry–Perot interferometer side and 10 pm/°C on the FBG side. It has been shown that the FBG can be used as a thermal compensating element.