Miniature all-silica fiber optic pressure and acoustic sensors

Abstract

We present a miniature diaphragm-based Fabry-Perot (F-P) interferometric fiber optic sensor fabricated by novel techniques for pressure or acoustic wave measurement that is only approximately 0.32 mm in diameter. By choosing different diaphragm thicknesses and effective diameters, we obtain a sensor measurement range from 5 to 10,000 psi (1 psi = 51.72 Torr) and a frequency response up to 2 MHz. In addition, the sensor's F-P cavity can be set from micrometers to millimeters with a precision of several nanometers. With the all-silica structure, the sensor is reliable, biocompatible, and immune to electromagnetic interference and has high-temperature sensing capability.

Fiber optic Fabry–Perot pressure sensor based on lensed fiber and polymeric diaphragm

“…A variety of Fabry-Perot interferometric sensors based on optical fiber have recently been studied and applied in various industrial areas to measure temperature, refractive index, strain, pressure, and fluid dynamics [1][2][3][4][5][6][7][8][9]. The Fabry-Perot sensors have drawn much interest owing to their advantages, such as dimensional compactness, high sensitivity, applicability in harsh environments, low cost, easy handling and alignment, immunity to electromagnetic interference (EMI) and multiplexing capability [1][2][3][4][5][6][7][8][9].…”

“…The Fabry-Perot sensors have drawn much interest owing to their advantages, such as dimensional compactness, high sensitivity, applicability in harsh environments, low cost, easy handling and alignment, immunity to electromagnetic interference (EMI) and multiplexing capability [1][2][3][4][5][6][7][8][9]. In particular, the Fabry-Perot sensors for the pressure measurement have a remarkable attention in a many applications such as medical, automotive, aerospace, gas and oil industries [9][10][11][12][13][14][15][16][17].…”

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

“…The linear demodulation method has a number of advantages such as high sensitivity, fast signal response, no sensitivity reduction, simple signal processing, and inherently low cost. These features make the linear demodulation particularly be used in dynamic measurement of small perturbations, such as the detection of ultrasonic [38][39][40], vibration [41], partial discharge [42], and dynamic strain [34]. The drawbacks of operating with the linear demodulation method are limited dynamic range and the challenge for the static operating point control or stabilization [39,43].…”

Method for Detecting the Inside of Coke Drum Using Acoustic Signals

“…The optical fiber F-P sensors have a wide range of response frequency, which is especially sensitive to low frequency signals [8]. In addition, the optical fiber F-P sensors have the advantages of a simple structure, light weight, antielectromagnetic interference, corrosion resistance, high sensitivity, and high security and stability, which overcomes the limitations of mechanical and electrical sensors [9,10].…”