Numerical Study On Transmission Properties From Special Photonic Crystal Fibres

With the avalanche of new optical materials and further investigation on soliton theory, it has afforded good opportunities for the development and the implementation of optical communications, facing with tremendous challenges at the same time. Owing to the fact that the results from numerical simulations can usually guide us to explore physical nature hidden behind natural phenomena, and that it will take quite some time and big dollars to explore physical character by using experimental approaches directly, and still further some experiments could not be carried out at present because of poor experimental conditions. Therefore, the effective method to solve the difficult questions above would be making numerical simulation tests by computers.Fundamental knowledge on solitons and two sets of software are introduced in my former half part thesis. In addition, we have programmed utility programs to simulate properties of PCFs and soliton transmission, validating our programs by comparing our results with those of a well-established method.In my latter half part thesis, we studied the transmission properties of optical pulses propagating in conventional optical fibres and special PCFs doped with active impurities or negative refractive materials, and the laws of mutual effects between soliton and Gauss quasi-soliton as well as the properties of optical amplification are obtained. With the help of the atom two-level theory, spontaneous emission from two-level atoms embedded in a photonic crystal is considered, and the conclusion that spontaneous emission could be controlled by adjusting the parameters of photonic crystals is reached. Our results are expected to provide theoretical proof for optical communications.