Multi-Parameter Sensing Technology Based On Microfluidic Integrated Resonant Microstructured Optical Fiber

For the complex,variable structure,and abundant mode characteristics,a new waveguide can be added into the fiber by optimizing micropore structure of the micro-structured optical fiber(MOF),which can control the guiding mechanism based on resonant coupling between modes.Owing to the high response sensitivity of the microfluidic integrated resonant microstructured optical fiber to physical parameters,such as temperature,strain,magnetic field etc,many refractive index sensors,temperature and stress sensors with ultra-high sensitivity have been extensively researched.However,the cross-sensitivity between physical parameters limits its application in the fields of dual-parameter or multi-parameter sensing.Therefore,by utilizing microfluidic integration technologies and resonant coupling to study multi-parameter sensor has important academic value and application.In this thesis,a resonant microstructured optical fiber is proposed by optimizing micropore structure of the MOF.The resonant coupling mechanism is investigated based on this fiber,which has potential applications to polarization filters and sensors.With resonant coupling and microfluidic integrated MOF,the cascaded multi-parameter sensor and the mixed-filled multi-parameter sensor is realized.The main research contents are as follows:1.The defect structure is added into cladding by optimizing micropore structure of the MOF,and a resonant microstructured optical fiber with a hybrid-circular-hole structure is proposed.this thesis numerically investigate the mode coupling process between core mode and cladding mode,the effects of structure parameters and temperature on resonant region,which shows that the fiber can be used as a tunable polarization filter.With the selective microfluidic integration technology,the temperature sensing of the Sagnac interferometer is realized,which shows that the integrated fiber can be used as a dual-parameter sensor.2.With microfluidic integration technology,a single-hole-microfluid-infiltrated mi-crostructured optical fiber(SHMI-MOF)and a photonic bandgap fiber(PBF)are fabricated,and the sensing characteristics of these two fibers are experimentally studied.The experimental results show that the temperature sensitivitis of SHMI-MOF and PBF are-13.94nm/°C and-5.39nm/°C,respectively,and the axial stress sensitivities are-34.48pm/?? and-29.52pm/??.3.For different sensing characteristics of these two fibers,a cascaded multi-parameter sensor based on PBF and SHMI-MOF cascaded fiber is proposed,which solves the cross-sensitivity problem between temperature and strain,and realizes the simultaneous measurement of temperature and strain.Then,a new sensor—mixed-filled multi-parameter sensor is proposed by utilizing single-hole infiltrating technology and full infiltrating technology,which brokes the limitations of the cascaded multi-parameter sensor,such as large size,high loss,complex fabricating,etc.