Study On The Dispersion And Negative Refractive Properties Of Crystal Fibres

As a new kind of developed fibers with many particular and useful characteristics, the photonic crystal fibers (PCFs) have recently attracted a great deal of interest both in theory and experiments. It's very difficult to give a qualitative or analytical analysis for a PCF due to its complicate structure,so numerical simulation is often necessary when one needs to analyze or design the characteristics of PCFs. The main contents are:1) In my thesis, we emphasize discussing solid core photonic crystal fibers' dispersion of properties. First, take the C_6v total internal reflection photonic crystal fibers for example, we found the dispersion's disciplinarian by change the structural parameters. Second, based on many forerunners' experience, by changing hollow core photonic crystal's shape, for example: triangle, hexagon, rectangle etc, which can find out the variety of dispersion. And localized fields of doped photonic crystal fibers, we know its effect on the dispersion. Last, according to above mentioned some conclusions, we may design more well special photonic crystal fibers.2) A full vector model is used to analyze the transmission properties of hexagonal air core photonic. By field pattern and curve, the internal regularity of energy flow, effective and effective core area is described directly. It is concentrated on how effective index, effective area and energy flow distribution can get the maximum by altering the structure parameters of the fiber and borehole spacing and proper parameters.3) Transmission spectrum from triangular structure PCs with equivalent negative index of refraction is studied with FDTD method in the paper, and the concept of equivalent index (n_eff) of refraction material is used to describe the optical transmission from such PCs. Because probability of spontaneous radiation is enhanced extremely by Bloch wave resonance stimulated radiation and photon tunneling, which makes energy highly location limited and the greatly strengthen their transmittance, the unilateral conduction of light and all-optical switching character are gained.