Ultra-flattened chromatic dispersion controllability using a defected-core photonic crystal fiber with low confinement losses.

The present paper describes a novel systematic solution to the problem of controlling the chromatic dispersion and dispersion slope in photonic crystal fibers (PCFs), using a structurally-simple PCF with a defected-core. By adjusting the size of the central air-hole defect we can successfully design an ultra-flattened PCF with low confinement losses, as well as small effective mode area. The design strategy is based on the mutual cancellation between the waveguide and the material dispersions of the PCF, by varying the size of the central defected region in the core. The verification of the ultra-flattened chromatic dispersion property of the proposed PCF is ensured with an accurate full-vector finite element method with anisotropic perfectly matched layers. The ultra-flattened dispersion feature, as well as the low confinement losses and the small effective mode area are the main advantages of the proposed PCF structure, making it suitable as a chromatic dispersion controller dispersion compensator, or as candidate for nonlinear optical applications.