A Composite Fabry-Perot Interferometric Sensor with the Dual-Cavity Structure for Simultaneous Measurement of High Temperature and Strain

Abstract

In this paper, an optical fiber composite Fabry-Perot interferometric (CFPI) sensor capable of simultaneous measurement of high temperature and strain is presented. The CFPI sensor consists of a silica-cavity intrinsic Fabry-Perot interferometer (IFPI) cascading an air-cavity extrinsic Fabry-Perot interferometer (EFPI). The IFPI is constructed at the end of the transmission single-mode fiber (SMF) by splicing a short piece of photonic crystal fiber (PCF) to SMF and then the IFPI is inserted into a quartz capillary with a reflective surface to form a single-ended sliding EFPI. In such a configuration, the IFPI is only sensitive to temperature and the EFPI is sensitive to strain, which allows the achieving of temperature-compensated strain measurement. The experimental results show that the proposed sensor has good high-temperature resistance up to 1000 °C. Strain measurement under high temperatures is demonstrated for high-temperature suitability and stable strain response. Featuring intrinsic safety, compact structure and small size, the proposed CFPI sensor may find important applications in the high-temperature harsh environment.

Review of acoustical and optical techniques to measure absolute salinity of seawater

“…With dr = 0.75179 x dS (Woosley et al, 2014), this translates into a poor resolution of 0.28 g kg -1 in salinity. Another kind of FP sensor was tested by Xia et al 2021 to measure high temperatures and strain. It consists of a silica-cavity intrinsic FP interferometer (IFPI) cascading an air-cavity extrinsic FP interferometer (EFPI).…”

Calibration Model Optimization for Strain Metrology of Equal Strength Beams Using Deflection Measurements

“…As a high-precision elastic sensitive component, equal strength beams have many advantages, such as good mechanical properties, high accuracy, and simple operation, and are often used in the study and calibration of vibration sensors [ 8 ], displacement sensors [ 9 , 10 ] and strain sensors [ 11 , 12 , 13 , 14 ]. In particular, the metrological calibration of FBG strain sensors with the strain and temperature coupling effects [ 15 ], can be possibly carried out using equal strength beams.…”

Fiber Optic Temperature Sensor System Using Air-Filled Fabry–Pérot Cavity with Variable Pressure

“…Temperature is a key parameter that needs to be monitored and controlled precisely in a wide range of applications, including industrial, chemical, structural, biomedical, and environmental aspects. For the last three decades, various techniques have been developed regarding fiber optic temperature sensors such as fiber-Bragg grating (FBG)-based sensors [ 5 ], tapered fiber [ 6 ], waveguide coupling devices using surface plasmon resonance [ 7 ], fiber ring laser demodulation [ 8 ], modified fibers (panda fibers [ 9 ], multicore fiber [ 10 ]), and interferometer-based sensors [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. Among these, temperature sensors based on Fabry–Pérot (FP) interferometers have proved to be an attractive option because of their additional advantages of simple structure and easy fabrication.…”

“…Researchers have also studied various methods for demodulation of sensor’s spectra. These FP interferometer sensors [ 24 , 25 , 26 ] are mainly based on dual cavity, where the composite wavelength signal is demodulated by using FFT with various algorithms such as white light interferometry [ 28 ], wavelet phase extraction [ 29 ], wavelet transform and polarized low-coherence interferometry [ 30 ], and coarse spectrum [ 31 ]. Most of them provide nm accuracy in cavity length measurement, which can result in error in temperature measurement at around 800 .…”