| Whispering gallery mode(WGM)optical microcavity with extremely high-quality factor(Q)value,extremely small mode volume and various structures or materials has broad research and application prospects in the fields of highly sensitive sensing detection,optoelectronic devices,nonlinear optics and basic physics.The research topic of this paper mainly includes the preparation,processing,and related research of microcavities,with research fields including mode field regulation,temperature,and biochemical sensing.The main research contents of this paper are as follows:1.Analysis of the characteristics and sensing performance of different types of microcavities.Firstly,the preparation and packaging methods of tapered fiber and microcavities with different structures were introduced.Secondly,two types of microcavity coupling detection systems were presented to study the transmission characteristics of microcavities.Finally,the Q-value,sensing performance,and mode field regulation characteristics of different microcavities were investigated,respectively.1)Q-value characteristics:the Q-value of hollow-core microbottle cavity is about 10~6～10~7,the Q-value of solid-core microbottle cavity is about 10~7～10~8,and the Q-value of microcylindrical cavity and coupled microcylindrical cavity is about 10~4.2)Sensing performance:the temperature sensitivity of the hollow-core microbottle cavity is 10.43 pm/℃,and the volume refractive index sensitivity is 6.31 nm/RIU,the temperature sensitivity of the solid-core microbottle cavity is 13.71 pm/℃.3)Mode field regulation characteristics:the microcylindrical cavity achieves the regulation of the complete period of the Fano resonance,while the coupled microcylindrical cavity achieves the regulation of mode splitting and controllable splitting spacing.2.A label-free DNA biosensor based on high Q-value optical microcavities functionalized by DNA nanostructured probes(DNPs)was proposed.By using DNPs,the surface functionalization quality of the sensor interface is improved,and the stacking and wrapping effects of the probes are reduced.The synthesis efficiency of DNPs is over 95%.Through fluorescence detection,the binding efficiency between DNPs and surface functionalized microcavities and target single-stranded DNA(ss DNA)is 92.8%and 94.11%,respectively.The proposed biosensor achieves an ultra-low detection limit of 260 a M,a detection time of about 40 min and single base mismatch recognition.3.A label-free DNA biosensor based on high Q-value optical microcavity functionalized by graphene oxide(GO)was proposed.The deposition of GO helps to enhance the interaction between light and matter.Through silanization treatment,GO was deposited uniformly on the surface of the microcavity.By activating the carboxyl groups on the surface of GO,effective connection between DNPs and GO is achieved.The proposed biosensor achieves an ultra-low detection limit of 79 a M,a detection time of about 48 min and single base mismatch recognition,and achieves DNA detection sensitivity of-1.522 pm/log f M.4.An ultra-high sensitivity flow rate detection based on a long pipeline-type high Q-value optical microcavity was proposed,and achieve direct detection of fluid based on microcavity and related applications under micro pressure state.A high Q-value long pipeline optical microcavity was prepared by adjusting the parameters of the cone-pulling machine,and the flow rate and light field of the microcavity were analyzed in detail through simulation.Without the help of other effects(Surface plasmon resonance,Fano,etc.),the sensing ability of the interaction between the microcavity light field and the cavity fluid is enhanced.The proposed sensor achieved high-performance flow rate sensing with a flow rate sensitivity of 0.27 pm/(μL/min)and a resolution of 1.43μL/min.Based on highly sensitive flow rate sensing,the application of enhancing the refractive index sensitivity of microcavity,detecting the properties of solution in the tube and the state inside the tube has been achieved. |
