Influence Of Temperature On The Stability Of Fabry-Perot Optical Fiber Hydrophone

Fiber hydrophone is a kind of sound press sensor based on multi-beam entire fiber-optical annularity F-P cavity intervene .It has a high sensitivity while the traditional piezoelectric type hydrophone doesn't without a parallel, but the stability is easy to be affected by the ambient temperature. Therefore there is a great challenge when we bring it into application.The background,principle,composition and sensitivity character of the type hydrophone which based on entire fiber-optical annularity int F-P ervenes are studied. The author put a high premium to research the phase changed by temperature in the annularity resonant cavity by theory, and make a conclusion that the sensitivity of phase changed by temperature of fiber hydrophone and the linear expanding efficient of material of hydrophone are in a linear relationship.Thereafter,the common way to improve the temperature stability of sensor and an idea that using a feedback method to improve the temperature stability of the fiber-optical hydrophone have been introduced.Then some simulations have been made to study the critical parameters which could affect the resonance curve and sensitivity of the fiber-optical hydrophone such as coupling coefficient and spectrum width of light.It is pointed out that the parameters above are not the same when they affect the function of hydrophone.So sound,light and electricity factors should been considered when we design the hydrophone.Finally, experiment is performed to testify the formula of sensitivity of phase changed by temperature and the stability of hydrophone affected by environment of water region is briefly discussed.