全固光子晶体光纤的特性研究

燕山大学工学硕士学位论文AbstractAll solid photonic crystal fiber has a variety of interesting properties such as easyfabrication as well as easily coupling with traditional fibers which have been widelyapplied in the fields like fiber lasers,fiber grating and etc.Usually,PCF guides light byone mechanism:index-guiding effect or bandgap effect.However there was not too muchstudy on the hybrid mechanism of those two effects in the past.In this paper,on the basisof analysis of the bandgap,dispersion and loss in all solid photonic bandgap fiber,a hybridall solid PCF is proposed and the guiding mechanism,dispersion is studied in this fiber.Ahigh birefringence all solid PCF with low confinement loss is designed in the end.Themain content is as follows.First,the properties,applications,developments and numerical simulation of all solidPCF are introduced.The full vector finite element method is elaborated in detail.Second,the bandgap,dispersion,confinement loss,effective area and other propertiesof AS-PBGF are investigated;their relations with structural parameters are given.It isuseful to provide the theory basis for designing AS-PBGFs with various propertiesThird,a hybrid all-solid PCF with micro-structured core is proposed.Themicro-structured core is consisted of pure silica and a high refractive indexgermanium-doped rod.The guiding mechanism is analyzed in detail and the influence ofthe central rod's radius on the dispersion,loss and other properties is studied.Simulationresults demonstrate that the guiding mechanism is transformed from bandgap effect intohybrid mechanism because of the central rod.The loss reduces 105~106 times.Byadjusting the radius of the central high refractive index rod,zero dispersion wavelength ofthe fiber can be tailored flexibly.The tunable band-width is up to 260 nm.Finally,by introducing a high refractive index elliptical rod,a high birefringence allsolid PCF with low loss is achieved whose cladding is consisted of elliptical rods.And theinfluence of the central rod on loss and birefringence is simulated.-IV-