Design And Experimental Study Of Fiber Optic Fabry-perot Acoustic Sensor

Sound pervades every corner of the world,it is everywhere.As an important disturbance parameter,sound has great research value for sound detection.The effect of sound transmission in space will be greatly affected,and highly sensitive sensors are required to effectively capture sound signals.Fiber optic Fabry-Perot sensor(F-P)has the characteristics of small size and high sensitivity.Making the F-P acoustic sensor into a vibrating film structure can effectively improve the detection sensitivity of the sensor.The effect of detecting acoustic signals in space can be realized.Therefore,this paper proposes to study the design and experimental study of optical fiber F-P acoustic sensor.The work done is as follows.First of all,a lot of research was carried out on the sound sensor.Describes common types of acoustic sensing technologies The research principle of different types of sound sensors and the research status of sound sensors at home and abroad are introduced.Secondly,the basic principles of acoustics are explored.The sensing principle of the Fabry-Perot sensor was analyzed.The interference spectrum of the Fabry-Perot sensor and the relationship between reflectivity were explored.Interference spectra under different reflectivity are simulated.Again,the sound sensor model of this design is analyzed.The relationship between interference contrast and cavity length was explored.The properties of the vibrating film were analyzed.The principle of film deformation and frequency response characteristics were studied.At last,a coating scheme that can solve the difficulty of capillary port coating is proposed.Finally,the designed sensor is simulated and experimentally studied.The relationship between interference period and cavity length is simulated.The relationship between pressure and shape variables was explored.Through the above simulation research,it is finally concluded that when the film material is selected as silver,the sensor made has the best effect.Testing of sensors with different cavity lengths,the experimental results show that the designed sensor can detect the acoustic signal.Sensors with smaller sensor cavity lengths measure a higher signal-to-noise ratio and a higher acoustic signal strength.