Filling Of Photonic Crystal Fibers And Photonic Crystal Fiber Grating

This work is financially supported by the National Basic Research Program of China (973), the National 863 High Technology Project, and National Science Foundation projects. Based on the requirement and target of the projects, firstly, PCF Bragg grating are investigated theoretically and experimentally. Moreover, the effects of filling high refractive index material (nematic liquid crystal, NLC) in PCFs on the transmission mechanism and propagation properties are studied by using plane-wave method and finite-element method (FEM), farther, several novel PCFs are proposed and designed. Lastly, we propose and demonstrate a clad-pumped Er3+/Yb3+-codoped fiber laser, which integrate all performances of broad-band tunable wavelength, uniform output power spectrum, high repeat frequency and high average power to together. The details are described as follows:1. The photonic bandgap theory based on total internal reflection (TIR) PCFs filled with by high index material (NLC) is proposed for the first time. Based on this theory, the effects of NLC-filled TIR-PCFs on the transmission mechanism and propagation properties are studied using plane-wave method and full-vector FEM. The results indicate that the transformation of transmission mechanism can be achieved when the TIR-PCFs are filled with NLC. Moreover, utilizing the difference of characteristics of modes in the PBGs, we achieve the shifting of PBG and model dispersion by modulating the refractive index of filled material based on PBG theory. Further, tunable photonic bandgap fibers are proposed and demonstrated.2. The effects of filling NLC in the TIR-PCFs on propagation properties of high birefringent PCFs are firstly studied based on PBG theory. The influences of NLC-filling on transmission mechanism and propagation properties are researched in detail; moreover, we compare those results with the cases of non-filled PCFs. The results show that transformation of transmission mechanism and much higher birefringence can be achieved after NLC-filling. Farther, we firstly demonstrate the realization of modulating PBG and modes of PBG-PCFs by changing refractive index filled of filled NLC by virtue of temperature or electric field, and finally tunable...