A Fiber Optic Interferometric Sensor for Dynamic Measurement

Authors: N. Sathitanon, S. Pullteap

Abstract:

An optical fiber Fabry-Perot interferometer (FFPI) is proposed and demonstrated for dynamic measurements in a mechanical vibrating target. A polishing metal with a low reflectance value adhered to a mechanical vibrator was excited via a function generator at various excitation frequencies. Output interference fringes were generated by modulating the reference and sensing signal at the output arm. A fringe-counting technique was used for interpreting the displacement information on the dedicated computer. The fiber interferometer has been found the capability of the displacement measurements of 1.28 μm – 96.01 μm. A commercial displacement sensor was employed as a reference sensor for investigating the measurement errors from the fiber sensor. A maximum percentage measurement error of approximately 1.59 % was obtained.

Keywords: Optical fiber sensors, dynamic displacement, fringe counting, reference displacement sensor.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1061607

References:

[1] E. UDD, Ed., Fiber Optic Sensor: An Introduction for Engineers and Scientists, New York, Wiley & Sons Inc., 1991.
[2] B. Culshaw and J. Dakin, "Optical Fiber Sensors: Systems and Applications", Artech House, vol. 2, Norwood, 1989.
[3] F. T. S. Yu and S. Yin, Fiber Optic sensor, New York, Marcel Dekker Inc., 2002.
[4] D. A. Krohn, "Fiber Optic Sensors: Fundamental and Applications", Instrument Society of America, Research Triangle Park, North Carolina, 1988.
[5] P. Fomitchov, T. W. Murray, and S. Krishnaswamy, "Intrinsic fiberoptic ultrasonic sensor array using multiplexed two-wave mixing interferometry", Appl. Opt., vol. 47 no. 2, pp. 1262-1266, 2002.
[6] A. Dandridge, Fiber Optic Sensors Based on the Mach-Zehnder and Michelson Interferometers in Fiber Optic Sensors: An Introduction for Engineers and Scientists, New York, Wiley & Sons Inc., 1991.
[7] N. Singh , S. C. Jain, A. K. Aggarwal and R. P. Bajpai, "Develop and experiment studies of fibre optic extrinsic Fabry-Pérot interferometric sensor for measurement of strain in structures", Current Science, vol. 86, no. 2, pp. 309-314, 2004.
[8] T. K. Gangopadhyay and P. J. Henderson, "Vibration: history and measurement with an Fabry-Pérot sensor with solid-state laser interferometry", Appl. Opt., vol. 38, no. 12, pp. 2471-2477, 1999.
[9] M. Born and E. Wolf, Principle of Optics, London, Cambridge University Press, 2002.
[10] P. C. Beard and T. N. Mills, "Extrinsic optical-fiber ultrasound sensor using a thin polymer film as a low-finesse Fabry-Perot interferometer", Appl. Opt., vol. 35, no. 4, pp. 663-675, 1996.
[11] T. K. Gangopadhyay, S. Chakravorti, K. Bhattacharya and S. Chatterjee, "Wavelet analysis of optical signal extracted from a non-contact fibreoptic vibration sensor using an extrinsic Fabry-Perot interferometer", Meas. Sci. Technol., vol. 16, pp. 1075-1082, 2005.