Development of an optical fiber hydrophone with fiber Bragg grating
A new type of optical fiber hydrophone is constructed with a fiber Bragg grating (FBG) based on the intensity modulation of laser light in an FBG under the influence of sound pressure. The FBG hydrophone shows linearity, with dynamic range about 70 dB. It can measure amplitude and phase of an acoustic field in real time, and operates in a wide range of acoustic frequency, at least from 1 kHz to 3 MHz. No signal distortion is observed in the detected signal. Because of the simplicity in its operating principle and geometry, an FBG hydrophone is expected to be an acoustic sensor of high practicality compared to a conventional optical fiber hydrophone.
Takahashi
N
Department of Applied Physics, National Defense Academy, Kanagawa, Japan. tak@cc.nda.ac.jp
Yoshimura
K
Takahashi
S
Imamura
K