Diaphragm-based optical fiber Fabry-Perot(F-P) pressure sensor uses the elasticdiaphragm to sense pressure, which modulates the cavity length of the F-P. This kindof sensor, which is simple in structure, high in sensitivity, easily controlled in theinitial length of the F-P cavity and has varied choices of the materials of the elasticdiaphragm, has a wide range of applications among fields.From the structures and fabrications of Diaphragm-based optical fiber F-Ppressure sensor, by combining the excellent characteristics of silicon in mechanic andoptic and the fast and efficient processing methods of laser processing,silicon-diaphragm-based fiber Fabry-Perot pressure sensor fabricated by using laserprocessing has been studied. The major work done is as follows:The sensing theory of diaphragm-based optical fiber F-P pressure sensor has beenexpounded and the deformation and sensitivity of the elastic diaphragm when loadedwith pressure is analyzed.By using the ANSYS software, with pressure loaded, diaphragms with differentpatterns of surface microstructures, varied sizes of patterns and misaligned or not issimulated, and the results of which are analyzed in the response of pressure loadingand optical sensing. Surface microstructures on silicon diaphragm are etched by usingNd:YAG-based3D laser processing system and the pressure sensors are packaged.Fiber F-P pressure sensor with cascaded structure of silica-glass(hollow)-silicaas its F-P cavity has been studied, and the fabricating requirements too. The basictheory and characteristics of anodic bonding are analyzed. The cascaded structure isfabricated and the corresponding sensors are packaged.Pressure test experiments on optical fiber F-P pressure sensors are performed.The results show: diaphragm-based optical fiber F-P pressure sensor withmicrostructures in perpendicular pattern on surface has a pressure sensitivity of12.7nm/kPa, a linearity of2.6%and an accuracy of2.445%; optical fiber F-P pressuresensors with cascaded F-P cavity has a pressure sensitivity of19.4nm/kPa, a linearityof8.79%and an accuracy of0.7379%. |