Influence Of Spectrum Width Of Optical Source On The Sensitivity Of Fabry-Perot Optical Fiber Hydrophone

Fiber hydrophone is investigated owing to high sensitivity and low weight. Due to its high sensitivity, fiber hydrophone is influenced easily by its factors and environment around it in the practical application. Light source spectrum width is one of factors which affect sensitivity.Structure and theory of Fabry-Perot fiber hydrophone are researched. The sensitivity of F-P fiber hydrophone, on the condition of ideal and nonideal light source, is received by theory ratiocination and experimental simulation. Great influence of spectrum width upon sensitivity of F-P fiber hydrophone is proved in the theory. Resonance and sensitivity curves are gotten making use of Matlab with the spectrum width changed. Meanwhile, several ways of stabilizing frequency are brought.Low noise PIN photodiode is used for photo-electricity conversion in the experiment. Pre-stage weak current is amplified by Transimpedance amplifier. After the output signal is filtered by low-pass filter and then amplified by differential and integral amplifier, compensation signal is gotten. Resonance curves are drawn when spectrum width of the light source are different. Sensitivity of fiber hydrophone is computed which is in accord with simulation.Sensitivity of Fabry-Perot fiber hydrophone will decline to 20dB as spectrum width increases to 2×10¹⁵ m, about one order.