Fabrication And Application Of Fiber-integrated Polymer Waveguide Gratings

Compared with traditional electronic sensors,fiber sensors have specific advantages and been used in various academic fields,such as ambient temperature or humidity sensing,biosensing,Oil flow velocity detection and so on.This dissertation main focuses on using femtosecond laser inducing two-photon polymerization technique to fabricate fiber-integrated polymer micro-structure.As follow:1.The dissertation reviews the domestic and international development of the femtosecond laser inducing two-photon polymerization technique and some nanomicro devices based on this technique used in fiber sensing field have been demonstrated.In addition,the development and application of polymer fiber Bragg gratings have been described.2.Then,the nonlinear interaction between femtosecond laser pulses and polymer material has been demonstrated,including two-photon absorption and two-photon polymerization.Based on the coupled mode theory,the Bragg coupled equation has been derived.3.Fiber-integrated polymer waveguide modes interferometer has been realized based on the femtosecond laser two-photon polymerization technique.The interference wavelength has been used to monitor the ambient temperature and the temperature sensitivity observed is 6.4 nm/℃.4.The fiber-integrated polymer Bragg waveguide gratings sensor has been realized by this technique.The fabrication process has been optimized and the modes simulation has been done to explore the polymer waveguide dispersion curve.Then,the Bragg resonance wavelength was used to monitor the ambient temperature,with a sensitivity of-220 pm/°C.5.The fiber-integrated polymer nano-Bragg waveguide gratings using for alloptical modulator has been realized by this technique.A 653 nm waveguide has been fabricated.Based on the photothermal effect and high thermo-optical coefficient of the polymer material,fiber-integrated all-optical modulator has been realized,with a fast temporal response of 176 ns.