Research On Fabry-Perot Sensor Device And Key Technology Based On Optical Fiber Endface Micromachining

Optical fiber Fabry-Perot(F-P)sensors with their application prospect in military,medical science,industry and agriculture have attracted the eyeballs of scientists.However,there are many problems such as the processing of F-P cavity,the measuring accuracy,measuring range and temperature interference hindering its application.The main work is provided as follows:1.The principle of F-P sensor is analyzed,the structure size of F-P is simulated,and the sensor temperature and strain sensing model is established,which provides a theoretical basis for the structural design,fabrication and optimization.2.According to the key technology of F-P structure prepared by chemical etching,a 40% concentration of HF is used to corrode the end face of the fiber,and it is welded by discharged with another fiber whose end face is flat.Furthermore,the F-P sensor is optimized by studying the key technologies such as corrosion time,concentration and arc discharge.Finally,F-P sensor with 35dB-fringe contrast is prepared.3.Experiment and analysis of the sensing characteristics of the F-P structure prepared by chemical etching.The temperature,strain and displacement test systems were designed and built to test their sensing characteristics.The experimental results show that the sensor is insensitive to temperature,and the strain and displacement sensitivity are 3.78 pm/?? and 0.01 nm/?m,respectively.4.A dual-parameter test method based on F-P structure is proposed and its sensing characteristics are studied.The F-P cascade Sagnac structure is designed and temperature and strain sensing test system are built with sensitivities of 0.71 nm/°C and 1.30 pm/??;Temperature and strain sensing system based on F-P cascade Mach-Zehnder structure is designed and built.The sensitivity of the sensor is 0.054 nm/°C and 2.73 pm/??,respectively,and the temperature and strain sensitivity matrix are established to realize the simultaneous measurement of the dual parameters.5.A method for fabrication of F-P structure using femtosecond laser at the fiber end face combined with arc discharge is proposed.Key technologies such as femtosecond laser processing principle,modulation depth,fiber core alignment and discharge power are studied to realize the preparation of F-P sensor,whose spectral contrast is greater than 10 dB and sensitivity is 2.82 pm/??.