Pressure sensor based on the fiber-optic extrinsic Fabry-Perot interferometer

Abstract

Pressure sensors based on fiber-optic extrinsic Fabry-Perot interferometer (EFPI) have been extensively applied in various industrial and biomedical fields. In this paper, some key improvements of EFPI-based pressure sensors such as the controlled thermal bonding technique, diaphragm-based EFPI sensors, and white light interference technology have been reviewed. Recent progress on signal demodulation method and applications of EFPI-based pressure sensors has been introduced. Signal demodulation algorithms based on the cross correlation and mean square error (MSE) estimation have been proposed for retrieving the cavity length of EFPI. Absolute measurement with a resolution of 0.08 nm over large dynamic range has been carried out. For downhole monitoring, an EFPI and a fiber Bragg grating (FBG) cascade multiplexing fiber-optic sensor system has been developed, which can operate in temperature 300 ℃ with a good long-term stability and extremely low temperature cross-sensitivity. Diaphragm-based EFPI pressure sensors have been successfully used for low pressure and acoustic wave detection. Experimental results show that a sensitivity of 31 mV/Pa in the frequency range of 100 Hz to 12.7 kHz for aeroacoustic wave detection has been obtained.

Advanced fiber-optic acoustic sensors

“…There are many demonstrations of extrinsic FPIs for pressure and acoustic sensing using optical fibers [20][21][22][23][24][25][26]. A summary of these works reported up to 2011 can be found in [27]. Since Murphy's work, new solutions to increase the dynamic range and high pressure variation have been proposed.…”

An arc tangent function demodulation method of fiber-optic Fabry-Perot high-temperature pressure sensor

“…However, most of the current phase demodulation systems are composed of large and expensive optical interferometers, which are difficult to be used in the practical engineering. In order to realize the application of the fiber-optic Fabry-Perot high-temperature pressure sensor in practical engineering, developing a high-precision, fast-rate, good-stability, and small-volume demodulation system is largely imperative [7][8][9][10].…”

Temperature profile of ex-vivo organs during radio frequency thermal ablation by fiber Bragg gratings

“…11,12 Among FOSs, fiber Bragg gratings (FBGs), whose sensing potentials have been widely demonstrated over the last decade in a number of sensing fields ranging from aerospace to civil engineering and environmental monitoring, 13,14 are fast becoming increasingly popular in the medical sensing field 15 as well. For example, FBGs have been experimented with for monitoring bone decalcification, 16 pressure monitoring, 17,18 controlling respiratory movements, 19 as well as specific sensors developed for pH and refractive index of liquids. [20][21][22] FBGs have also been used as temperature sensors, 23 as well as in vibration measurement during treatment of atrial fibrillation.…”