Research On Fiber Optic Micro Pressure Sensor Based On Graphene Diaphragm

As a new type of pressure sensor,the optical fiber pressure sensor has characteristics of miniaturization,high sensitivity,high accuracy,and strong resistance to electromagnetic interference,and is widely used in industrial production and defense construction.Graphene has the advantages of small thickness and high breaking strength.The use of graphene as a pressure sensitive membrane material can greatly increase the sensitivity of the pressure sensor.The design,manufacture and testing of the sensor is introduced in this paper.At the same time,the wavelet transform neural network based on genetic algorithm is used to compensate the temperature of the sensor in order to eliminating temperature changes and measuring errors.The main work is as follows:In this paper,a fiber-optic Fabry-Perot pressure sensor based on graphene diaphragm is designed.The relationship between the thickness of the sensitive film and the reflectance of the film was analyzed.The mechanical properties of the film were modeled and analyzed using ANSYS.The effect of Fabry-Perot cavity on the overall performance of the sensor was studied using optical transmission matrix theory.Finally,the best range of Fabry cavity length was 40-60 ?m.In this paper,a Fabry-Perot cavity was fabricated by chemical etching.A Fabry-Perot cavity with a length of approximately 52.71,m was obtained by etching a multimode optical fiber,and a graphene diaphragm was adhered to obtain a fiber-optic Fabry-Perot sensor.The sensor is then packaged and tested for performance.Finally,temperature compensation eliminates the effect of temperature on the sensor performance.At room temperature,the maximum deflection of the sensitive film is about 5.16?m,the sensitivity is about 51.6nm/kPa,the linear fitness is 98.03%,and the drift error after compensation is about 0.2nm/?.