Optimization And Plating Experiment On The End Reflectivity Of Fiber Optic F-P Sensor

The fiber optic Fabry-Perot sensor is used broadly in engineering for long term on line monitoring of large structure since it has the advantages of small bulk, high sensitivity, stable performance, simple structure, ability of remote signal processing and so on. According to the theory of demodulation of F-P sensor, the quality of F-P sensor's output signal directly affects the accuracy and measure distance of the whole F-P sensing system, and it also determines the requirements of the performance of the light source and light detector constituting the demodulation system. However, there is transmitting loss inevitably when light transmits in F-P cavity, which leads to poor signal quality and high cost. This limits the application of F-P sensor in engineering greatly. Since the increase in end reflectivity of reflective fiber can improve the signal quality, and there is an optimal reflectivity corresponding to the cavity length, to find a proper reflectivity is the key issue when making a F-P sensor. Therefore, making optimization on end reflectivity of fiber is very important, which can improve the performance of the whole F-P measuring system.On the other hand, the end reflectivity of fiber is about 0.04 when it isn't being treated particularly. In order to attain the required end reflectivity, plating is necessary. Vacuum evaporation and sputtering are staple plating methods, but they all have shortcomings in common such as needing special equipments, complex technics, high cost, and plating needs to be carried out in high temperature circumstance. Thus, these two methods are still improper for fiber plating. However, electroless plating can be done under normal temperature, it also has many other advantages such as simple tehnics, low cost etc. It can also cut the cost through electroless plating.Optimization on end reflectivity of reflective fiber is done in this paper, and the rule of electroless plating for fiber is investigated through lots of experiments, optimization on electroless plating technics is also done by means of orthogonal experimental method. Detailed information is al follows:①The background and importance of this study is discussed.②The signal form of F-P sensor is investigated through simulation according tothe theory of fiber optic F-P sensor, and the intensity and contrast ratio of F-P sensor's signal are discussed. The transmission loss of light in F-P cavity and its effect on the output signal of F-P sensor is discussed subsequently. Furthermore, it is brought...