Photonic crystal fibers with broadband nearly-zero ultra-flattened chromatic dispersion and improved effective mode area

We have presented a novel design of PCF in order to control the dispersion and the dispersion slope of index-guiding PCFs. This analysis includes a thorough description of the dependence of the fiber geometrical dispersion on the structural parameters of a PCF, which allows us to design PCF with both ultra-flattened and nearly-zero dispersion in a wide wavelength range. Numerical results show that a PCF with dispersion of 0±0.75ps/(nm-km) over 380nm bandwidth from 1.39μm to 1.77μm can be designed. Moreover, a small effective mode area is possible so that we can get high nonlinearity. PCFs with these novel properties have potential uses in communication systems, optical parametric amplification and so on. The software COMSOL based on finite element method with anisotropic perfectly matched layers is used to analyze the dispersion properties and effective mode area in a PCF with two-ring air holes.