An optical fiber hydrophone using equivalent phase shift fiber Bragg grating for underwater acoustic measurement

Abstract

An optical fiber hydrophone based on equivalent phase shift fiber Bragg grating (EPS-FBG) with temperature compensation package provides an improvement of sensitivity in underwater acoustic measurement at wide frequency range, from 2.5 kHz to 12 kHz. The acoustic pressure is transduced into elastic vibration of a circle metal disk, resulting in an intensity modulation of the reflected light wave back from fiber Bragg grating (FBG). Experiment shows that the packaged EPS-FBG hydrophone has a minimum detectable acoustic pressure of about 500 [inline-graphic not available: see fulltext] at 5 kHz and achieves about 18-dB improvement of acoustic pressure sensitivity compared with a regular apodized FBG hydrophone.

Keywords

Optical fiber hydrophone / acoustic pressure sensitivity / equivalent phase shift fiber Bragg grating / temperature compensation package

References

[1] Rao Y. J., Wang Y. P., Ran Z. L., Zhu T.. Novel fiber-optic sensors based on long-period fiber gratings written by high-frequency CO₂ laser pulses. J. Lightwave Technol., 2003, 21(5): 1320-1327.

[2] Monma H., Fujiwara N., Iwase R., Kawaguchi K., Suzuki S., Kinoshita H.. Monitoring system for submarine earthquakes and deep sea environment. Proc. MTS/IEEE OCEANS’97, 1997, 2, 1453-1459.

[3] Yuan Y. Q., Shi B. W., Liu Z. J.. A new multilayer planar PVDF standard hydrophone and its applications. IEEE Trans. on Ultrason., Ferroelect., and Freq. Contr., 1995, 42(5): 958-964.

[4] Jiao B. L.. Investigation on piezoelectric helix for use as a hydrophone. IEEE Trans. on Ultrason., Ferroelect., and Freq. Contr., 1999, 46(6): 1446-1449.

[5] Bucaro J. A., Dardy H. D.. Fiber-optic hydrophone. J. Acoust. Soc. Am., 1977, 62(5): 1302-1304.

[6] Cranch G. A., Nash P. J., Kirkendall C. K.. Large-scale remotely interrogated arrays of fiber-optic interferometric sensors for underwater acoustic applications. IEEE Sensors J., 2003, 3(1): 19-30.

[7] Wang Z. F., Hu Y. M., Meng Z., Ni M.. Pseudo working-point control measurement scheme for acoustic sensitivity of interferometric fiber-optic hydrophones. Chin. Opt. Lett., 2008, 6(5): 381-383.

[8] Cranch G. A., Nash P. J.. Large-scale multiplexing of interferometric fiber-optic sensors using TDM and DWDM. J. Lightwave Technol., 2001, 19(5): 687-699.

[9] W. T. Zhang, F. Li, Y. L. Liu, and H. Xiao, “FBG hydrophone: theory and experiment,” in Opt. Fiber Sensors Conf., 2008. APOS’08, 1st Asia-Pacific, Chengdu, Nov. 7–9, pp. 1–4, 2008.

[10] Takahashi N., Yoshimura K., Takahashi S., Imamura K.. Development of an optical fiber hydrophone with fiber Bragg grating. Ultrasonics, 2000, 38(1–8): 581-585.

[11] Sheng H. J., Fu M. Y., Chen T. C., Liu W. F., Bor S. S.. A lateral pressure sensor using a fiber Bragg grating. IEEE Photonics Technol. Lett., 2004, 16(4): 1146-1148.

[12] A. Cusano, S. Campopiano, S. D’Addio, M. Balbi, S. Balzarini, M. Giordano, and A. Cutolo, “Plastic coated fiber Bragg gratings as high sensitivity hydrophones,” in 5th IEEE Conf. on Sensors, Daegu, pp. 166–169, 2006.

[13] Yang J., Zhao Y., Ni X. J.. Development of novel fiber Bragg grating underwater acoustic sensor. Acta Optica Sinica, 2007, 27(9): 1575-1579.

[14] Dai Y. T., Chen X. F., Jiang D. J., Xie S. Z., Fan C. C.. Equivalent phase shift in a fiber Bragg grating achieved by changing the sampling period. IEEE Photon. Technol. Lett., 2004, 16(10): 2284-2286.

[15] Wang X., Yu C. X., Yu Z. H., Wu Q.. Sampled phase-shift fiber Bragg gratings. Chin. Opt. Lett., 2004, 2(4): 190-191.

[16] Yoffe G. W., Krug P. A., Ouellette F., Thorncraft D. A.. Passive temperature-compensating package for optical fiber gratings. Appl. Opt., 1995, 34(30): 6859-6861.

[17] Timoshenko S., Woinowsky-Krieger S.. Theory of plates and shells, 1959, New York: McGral-Hill Book Company