| Microstructured optical fiber（MOF）owns the large flexible design of fiber structure and unique light-guiding mechanism.With the modulation of the shape,size and distribution of the air holes in MOF,the optical properties can be adjusted effectively to satisfy various requirements.The existence of air holes can not only be used as the transmission channels of guided light,but also provides the possibility to insert gases or liquids,enables strong interaction between light and samples,which shows great significance in fiber sensing applications.In this paper,based on the MOF we researched its gas,refractive index（RI）and temperature sensing characteristics,as well as the polarization filtering properties.The dissertation mainly includes following contents and innovations:1.Using the photonic bandgap（PBG）MOF as the gas cell,we built the dual-wavelength intra-cavity gas detecting system.Due to the mode competition phenomenon,the designed sensor can realize the acetylene minimum detectable gas concentration（MDGC）of 10.42 ppm V,6.44 times higher than that of single-wavelength intra-cavity gas detecting system.2.We designed the exposed-core（EC）grapefruit fiber（GF）MOF surface plasmon resonance（SPR）sensor to solve the metal coating problem of the inner air hole and repetitive analyte filling problem.The sensing performance of the designed sensor is analyzed at the RI range of 1.33-1.42 using the wavelength and amplitude modulations,the largest wavelength sensitivity of 11800 nm/RIU and largest amplitude sensitivity of 204 RIU-1 are obtained,which can realize the high resolution detections of 8.47×10-6 RIU and 4.90×10-5 RIU,respectively.By placing the silver nanoparticle or the dielectric core-silver shell composite silver nanoparticle（CSN）at the exposed core region of the EC GF MOF,the metal coating especially uniform metal coating operations can be replaced to simplify the processing.The influence of the CSN location in GF and the diameter and RI of the dielectric core,as well as the silver shell thickness of CNS to the sensitivity of the designed sensor are analyzed.The theoretical wavelength sensitivity of 7903.03nm/RIU is obtained in high linearity.3.The six-hole GF MOF localized SPR（LSPR）temperature sensor filled with CNS and liquid with large thermo-optic coefficient was designed with theoretical temperature sensitivity of-17.8 nm/℃.The CNS location,length and structural parameters which will affect the temperature sensing performance are all analyzed.In experiment,we built the temperature sensing system by filling silver nanoparticles and liquid mixture（ethanol and chloroform）into the cladding air holes of the LMA-10 MOF.The temperature sensing performances of the sensor at the range of 25℃to 60℃are researched with different mixing ratios and the temperature sensitivity of-2.08 nm/℃is obtained in experiment.4.The polarization filtering properties of MOF based SPR were researched theoretically.We realize the narrow band single-mode single-polarization filtering at the communication band of 1310 nm with filtering loss of 500 d B/cm and full width of half maximum of 23 nm,also realize the orthogonal polarization filtering with losses of 53.1 d B/cm and 305.1 d B/cm,at the communication bands of 1310 nm and1550 nm,respectively.The 20 d B working bandwidths of the orthogonal polarization filter are 62 nm and 133 nm,respectively. |
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