Investigation On Slow Light In Photonic Crystal Fiber Bragg Gratings

Photonic crystal fiber Bragg gratings(PCFBG) is a novel technology in the pastfew years, which combines the merits of photonic crystal fiber(PCF) and fiber Bragggratings(FBG) together, these excellent characteristics make it widely applied in opticalcommunication fields, and become a hot topic in scientific researches.Recently, the investigation of slow light in fiber arouses much more attention innational scientific research fields. slow light characteristics of fiber can realize manyapplications which can not be achieved by exploiting the conventional fiber, such asoptical buffers, optical storages, interferometers, optical switches, and so on. In thisthesis, the slow light in PCFBG is investigated by Improved full vector Effective IndexMethod(IEIM) and the Coupled-mode theory, and the influences of the variousparameters on slow light characteristics are relatively completely analyzed, whichprovided the basis theories for designing the slow light delay devices based on PCFBG.In this thesis, the main contents and innovations are listed as follows:1. PCFBG is constructed simulation models by using Improved full vectorEffective Index Method(IEIM) and the Coupled Mode theory. Furthermore, the slowlight in PCFBG is analyzed.2. The spectra of slow light in PCFBG is numerically simulated, and the influencesof the various parameters on slow light in PCFBG is analyzed. The calculated resultsindicate that PCFBG of1.06centimeter can produce linear delay of about52ps; whenthe grating length and grating period kept constant, the wavelength in slow light peaksof PCFBG shows a blue shift and the slow light in PCFBG decreases gradually as thefilling factor increasing; PCFBG has higher slow light delay with increasing the gratinglength. Finally, the lowest slow light is found out, which exists in the vicinity of theside-lobes where the maximum group velocity is c/197after optimizing the parameters.3. The group velocity and the phase of PCFBG are investigated, which furthertestified the correctness of above theories, and the sensitivity of phase variation is foundout in the vicinity of the side-lobes where exists slow light, these provide the theoreticalbasis for designing the slow light delay devices and sensors based on PCFBG.