Share Email Print
cover

Proceedings Paper

Optical fiber acoustic and ultrasonic sensor based on Fabry-Perot interferometry
Author(s): Zhenwu Guo; Weixiang Li; Dapeng Zhang; Guiling Sun; Xian Zhang
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

We designed a optical fiber acoustic and ultrasonic sensor probe based on Fabry-Perot interferometry, and gave the principle structure of the sensor: The two mirrors of Fabry-Perot interferometer are composed of the fiber's end face and the aluminum thin diaphragm, outside sound wave will force the thin diaphragm vibration, it is also to say the Fabry-Perot cavity length varies with the sound wave, thus the output intensity of the interferemeter is modulated by the wave, at last the photodetector(PD) transforms the light intensity signal to electric current signal. The thickness of the aluminum thin diaphragm is 10μm only, and its radius is 1mm, as a result the sensitivity of the sensor is very high. But if placing the sensor in liquid at a deep point, the static pressure would make the thin diaphragm crushed because the static pressure of the liquid is very strong compared with sound wave. For this reason, we design a kind of small scaled air bag linked with the Fabry-Perot cavity which spread the sensor an ability of being able to stand of the static pressure. The maximum of static pressure the sensor could stand has improved from 0.3 MPa to 10 MPa above, so the sensor may work normally at point of 1000m under water surface. The result of experiment in water show that the sensor sensitivity reaches -162dB(0dB=1rad/μPa), the frequency response range is from 1KHz to 5 MHz. The sensor is fit for detecting acoustic and ultrasonic signals in liquid.

Paper Details

Date Published: 22 February 2008
PDF: 9 pages
Proc. SPIE 6622, International Symposium on Photoelectronic Detection and Imaging 2007: Laser, Ultraviolet, and Terahertz Technology, 66221U (22 February 2008); doi: 10.1117/12.790915
Show Author Affiliations
Zhenwu Guo, Nankai Univ. (China)
Weixiang Li, Nankai Univ. (China)
Dapeng Zhang, Academy of Military Transportation (China)
Guiling Sun, Nankai Univ. (China)
Xian Zhang, Academy of Military Transportation (China)


Published in SPIE Proceedings Vol. 6622:
International Symposium on Photoelectronic Detection and Imaging 2007: Laser, Ultraviolet, and Terahertz Technology

© SPIE. Terms of Use
Back to Top