A Novel Photonic Quasicrystal Fiber with Broadband Large Negative Dispersion

A broadband highly dispersive fiber based on a dual-concentric-core photonic quasicrystal fiber (PQF) is designed for chromatic dispersion compensation. The fiber is composed of pure silica background and air-holes without doping. The fundamental supermode has a large negative dispersion value of about −9600 ps⋅nm⁻¹⋅km⁻¹ over an optical communication band around 1550 nm and a full width at half maximum (FWHM) of 40 nm. By adjusting the structural parameters, a dispersion of −2250 ps⋅nm⁻¹⋅km⁻¹ around 1550 nm with the FWHM exceeding 280 nm is obtained and the dispersion-bandwidth product can reach 630 GHz⁻¹⋅km⁻¹, which is the highest value of dispersion-bandwidth product from pure silica fibers reported so far.