New nonlinear and dispersion flattened photonic crystal fiber with low confinement loss

Abstract

A new nonlinear dispersion flattened photonic crystal fiber with low confinement loss is proposed. This fiber has threefold symmetry core. The doped region in the core and the big air-holes in the 1st ring can make high nonlinearity in the PCF. And the small air-holes in the 1st ring and the radial increasing diameters air-holes rings in cladding can be used to achieve the dispersion properties of the PCF. We can achieve the optimized optical properties by carefully selecting the PCFs structure parameters. A PCF with flattened dispersion is obtained. The dispersion is less than 0.8ps/(nmkm) and is larger than −0.7ps/(nmkm) from 1.515μm to 1.622μm. The nonlinear coefficient is about 12.6456W−1km−1, the fundamental mode area is about 10.2579μm2. The confinement loss is 0.30641dB/km. This work may be useful for effective design and fabrication of dispersion flattened photonic crystal fibers with high nonlinearities.