Design on a photonic crystal fiber with high nonlinearity and flattened dispersion for Raman soliton self-frequency shift

A photonic crystal fiber (PCF) with high nonlinearity and flattened dispersion is designed. The structure of PCF is in a hexagon lattice. The larger air holes in the outer rings are used to confine the light field into the core region to enhance the nonlinearity, and the flattened dispersion can be achieved by adjusting the diameters of six smaller air holes in the first ring. By optimizing the sizes of the smaller and larger holes, the PCF can achieve high nonlinearity of 19 W(-1)km(-1) and low dispersion of 80.96 ps/(nm.km) with the fluctuation dispersion range of 8.49 ps/(nm.km) within the wavelength range of 1400 to 1800 nm. The PCF designed can find important applications in effectively realizing Raman soliton self-frequency shift and generating supercontinuum.