Research On The Spectral Characteristics And Applications In WDM Systems Of Photonic Crystal Fiber Grating

In recent years, photonic crystal fiber grating (PCFG) has been applied more and more inoptical fiber communication system such as WDM and OADM because of its excellent propertiesand related research progress.The paper firstly introduces the present situation of the research anddevelopment as well as the application in optical communication of PCFG at home andabroad.Then research and calculation methods of PCF and PCFG such as Coupled Mode, TheoryFourier Transform Method, Transfer Matrix Method, of Finite Element Method and EffectiveRefractive Index Method are briefly introduced.The Effective Transmission Modes of photonic crystal fiber structured with square symmetryhole cladding were analyzed by the Finite Element Method, and the effective refractive indexes ofthe modes at different wavelength were got. The reflection spectrums of this photonic crystal fibergrating were computed and simulated by Coupled Mode Method and Transmission Matrix Method.Moreover, the differences of reflection spectrums with different diameter-to-pitch ratio werecompared. Then we got optimized reflectance spectrum apodized by Gaussian function. Theoreticalcalculations and simulation result show that the effective refractive index of every mode declineslinearly approximate as wavelength rises, and reflection spectrum of the photonic crystal fibergrating mainly lies on the diameter-to-pitch ratio of cladding structure. Then we studied the tuningcharacteristics of temperature and strain of S-PCFBG. The simulations show that the stresssensitivity of S-PCFBG is low, and the temperature sensitivity is relatively high.On this basis, the tuning characteristics of S-PCFBG structured with square symmetry holecladding and MZI interferometer can be further studied and applied to multi-channel OADMreconfigurable.