Research On Fiber-optic Hydrophone For Wide Range Of Signal

Fiber-optic hydrophone is a sensor system which can detect ocean acoustic signal. It has been researched and developed by the enormous values in military and civil area. Fiber-optic hydrophone has many advantages such as larger bandwidth, higher sensitivity,anti-electromagnetic interference, no complicated equipment in the underwater, and form arrays easily and etc. Comprehensive the above characteristics, so the research and develop of the fiber-optic hydrophone has been attached great importance to many countries.According to the broad band properties of underwater sound signal and the complexity of the underwater acoustic field, fiber optic hydrophone unit cannot obtain all the information of the detecting targets. So the research on fiber-optic hydrophone array for broad band signal is of great significance.First of all, this article introduced the structure and working principle of the interferometric fiber-optic hydrophone, light polarization is described. And analyze the polarization resistance decline and random phase decline phenomenon.Second, based on the detection scheme to improve phase generated carrier modulation.Under the condition of different carrier, affecting the maximum dynamic range are analyzed. Factors affecting the effect of demodulation respectively, including the signal amplitude,frequency, bandwidth and the size of the size of the carrize signal frenquency are simulated, and the simulation results are analyzed. Concluded that the carrier frenquency is larger, the greater the system dynamic range is larger. At the same time, with the decrease of the carrier frenquency, the increase of signal frenquency, with the increase of signal amplitude and the demodulation system effect is worse.At last, analyze the array multiplexing technique, time-division multiplexing technology adopted in this paper. The overall block diagram is given. It provides reference for future research and development of fiber-optic hydrophone array.