Chromatic dispersion control in photonic crystal fibers: application to ultra-flattened dispersion

In order to control the dispersion and the dispersion slope of index-guiding photonic crystal fibers (PCFs), a new controlling technique of chromatic dispersion in PCF is reported. Moreover, our technique is applied to design PCF with both ultra-low dispersion and ultra-flattened dispersion in a wide wavelength range. A full-vector finite element method with anisotropic perfectly matched layers is used to analyze the dispersion properties and the confinement losses in a PCF with a finite number of air holes. It is shown from numerical results that it is possible to design a four-ring PCF with flattened dispersion of 0 +/- 0.5 ps/(km.nm) from a wavelength of 1.19 mum to 1.69 mum and a five-ring PCF with flattened dispersion of 0 +/- 0.4 ps/(km.nm) from a wavelength 1.23 mum to 1.72 mum. (C) 2003 Optical Society of America.