| Interference optical fiber photonic devices,as the important medium to realize various optical technology applications,have been widely used in sensor monitoring system,communication system,laser and other fields.The advantages include faster information transmission,anti-electromagnetic interference,lower cost and etc.In this paper,the research based on interference optical fiber photonic devices mainly focuses on vital signs sensing and tunable filters.The traditional vital signs monitoring technology mainly is based on piezoelectric acceleration sensor,Doppler radar,capacitive electrode,magnetic impedance sensor and infrared thermal imaging,where the problems of electromagnetic interference,complex operation,expensive equipment and power on safety can not be avoided.Besides,the traditional tunable filter mainly depends on mechanical tuning structure,and its performance is limited by mechanical tuning structure,which causes the slower tuning speed,lower precision and poorer repeatability.This paper is intended to fabricate the interference optical fiber photonic devices based on fiber microcavity interferometer and multimode fiber interferometer.Starting from the above problems,combined with the advantages of optical fiber photonic devices,explore their potential applications in vital signs sensing and all-optical tunable filter.The main research results are as follows:Firsty,a fiber-optic microcavity photonic device based biaxially oriented polypropylene(BOPP)film for the breathing process monitoring is proposed.The spiral device with controllable spectral characteristics is made by 3D printing technology.Based on the theory o f microcavity interference and the normal deformation theory of BOPP film,the relationship between the response of new structure device and the respiratory pressure is clarified.It turns out that the press ure sensitivity is-0.581 nm/Pa.Finally,the device is fixed on the medical respirator,and its function to monitor the breathing process is verified by experiment.Secondly,a fiber microcavity photonic device based on ethyl alpha-cyanoacrylate(EtCNA)for monitoring heart rate is proposed.Based on the microcavity interference theory and linear cantilever deflection theory,the relationship between the response of new s tructure device and the heart rate low frequency vibration is clarified.The results shows that the strain sensitivity is 2.57pm/?N.The device is applied to monitor the heart rate of wrist,chest and neck,and the experiments to monitor the heart rate are conducted.Thirdly,a grid structured planar fiber photonic device based on multimode fiber interferometer for monitoring animal sleep is proposed.According to multimode fiber interference theory and multi-point transfer theory,the response of network structure device to body movement during sleeping is clarified.The pressure sensitivities of the device are-11.2 pm/Pa?-9.7 pm/Pa and-8.3 pm/Pa at the wavelength of 1540 nm,1550 nm and 1560 nm,respectively.In order to verify the monitoring ability,the experiment to monitor the dog's sleep are conducted for one week.At last,a graphere mirror based all-optical tunable fiber microcavity filter is proposed.The transmission spectrum of the filter occurs the blue shift under 980-nm pump,while its wavelength linear tuning rate and the range reach 103.69 pm/mW and 8.30 nm,respectively.Based on the above researches,GN/EP-air-GN/EP composite microcavity filter and GN/EP solid microcavity filter are fabricated by using graphene/epoxy resin(GN/EP)composite.The all-optical tunable characteristic of the two filters are analyzed theoretically and experimentally.Under980-nm pump,the wavelength linear tuning rate of the two filters are-352 pm/mW and-840 pm/mW,respectively,and the wavelength tuning ranges are 11.03 nm and25.54 nm,respectively. |
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