Research On Key Technology Of Fiber Optic Atmospheric Pressure Sensor

With the improvement of optical fiber manufacturing technology and the advancement of optical fiber sensing technology,optical fiber sensors that can be used to measure multiple parameters have been rapidly developed.Displacement and deformation are important measurement parameters and play an important role in scientific research.Using the modulation and demodulation technology of optical fiber sensing,the sensitivity of the optical fiber sensor is greatly improved while reducing the impact on the measurement.Due to the gradual industrialization of optical fiber sensors,the production cost is effectively reduced,and it is suitable for promotion to practical applications.In the field of aerospace,there is an urgent need for new sensors that can measure air pressure with high precision to provide high-altitude atmospheric data;at the same time,at higher altitudes,we also need to measure air pressure more accurately to derive altitude.In the field of industrial production,the harsh environment(strong corrosion,strong interference)also requires high-precision measurement of the production air pressure.Under these extreme conditions,traditional electronic sensors cannot meet the needs of production and life.At this time,fiber optic sensing technology has entered the sight of people's research.Compared with the traditional measurement sensor,the optical fiber has excellent light transmission performance,low loss for light waves,and a bandwidth 5 orders of magnitude higher than microwave.The detection of pressure and displacement is currently the most widely used direction of light sensors.Among them,reflective intensity fiber sensors can achieve non-contact measurement and low design and manufacturing costs,so they are the most widely used in this field.This subject comes from replacing the role of traditional electronic sensors such as airspeed tubes in the measurement of air pressure.By designing the reflective surface structure of two different materials,the parameters of the optical fiber pressure sensor with different structures are simulated based on the Gaussian distribution of the light field distribution model.Effect on output light intensity.The main contents of this article are:(1)The article introduced the development process of optical fiber sensing technology and various types of optical fiber sensors and characteristics,expounded the research background and significance of the subject,and clearly analyzed the following research directions.Subsequently,the basic structure and working principle of the two types of optical fiber sensors designed in this paper are introduced,and the light field distribution model emitted by the fiber is introduced,and the output light intensity of the fiber is derived according to the Gaussian distribution model.(2)The article completed the design of the fiber-optic barometric pressure sensor with displacement reflection surface,using the reflection surface of rigid material.When the pressure difference between the inside and outside of the housing changes,the distance between the reflective surface of the rigid material and the fiber end of the fiber will change,so that the light intensity of the receiving fiber will change.The Gaussian distribution model is used to process the reflected light cone.The output characteristic parameters of the optical fiber pressure sensor with this structure and the influence of each parameter on the output characteristic function are studied.(3)The structure of the optical fiber pressure sensor with deformed reflection surface is designed,and the reflection surface of the elastic material is used.Analyze the relationship between the pressure and the central deformation of the diaphragm,and analyze the impact on the radius w(d)of the reflected light cone when the diaphragm has different concave and convex deformations due to the different pressures on both sides of the diaphragm.Simulate and analyze two different situations to get the effect of each parameter on the output characteristics.(4)The article analyzed the disturbance factors of the system,and added a receiving fiber to optimize the system.Thereby reducing the influence of the light source and reflecting surface characteristics on the system.It is determined that the structure with equal cores and unequal spacing is used to compensate the light intensity disturbance and linear interval of the optical fiber pressure sensor.And analyze the influence of the difference between the receiving fiber spacing and the numerical aperture of the outgoing fiber.The key technology of this paper is to calculate and analyze the output light intensity of the optical fiber pressure sensor to obtain the influence of various parameters on the output light intensity of the system.Then compensate for the factors of light intensity disturbance,and analyze the compensation structure to determine the optimal structure.This article introduces the principle structure of the optical fiber pressure sensor of the reflective light emphasis type as comprehensively and meticulously as possible,studies the output characteristics of the optical fiber pressure sensor using rigid materials and elastic materials,and proposes a good solution to the measurement of air pressure.Great research significance and value.