Novel design of photonic crystal fibres with low confinement losses, nearly zero ultra-flatted chromatic dispersion, negative chromatic dispersion and improved effective mode area

A novel photonic crystal fibre (PCF) with a low confinement loss and nearly zero ultra-flatted chromatic dispersion and negative chromatic dispersion at a wide telecommunication window is presented. Important PCF design parameters, such as the effects of air holes and geometrical parameters on the effective index, confinement losses, chromatic dispersion and effective mode area, have been thoroughly investigated by employing the full vectorial finite element method. Significant reduction of the confinement loss and low chromatic dispersion of the PCF, with three rings of air holes, has been obtained by carefully incorporating additional air holes.