A broadband ultra flattened chromatic dispersion microstructured fiber for optical communications

A double-cladding microstructured fiber (MF) is proposed in this paper. The inner cladding of this optical fiber is composed of elliptical air holes and silica. The dependence of dispersion on the diameter of the air holes, the pitch, and the axes of the elliptical holes is investigated numerically. The proposed fiber possesses an ultra flattened dispersion curve over a wide wavelength range, and its dispersion value is small. The effective mode area is approaching to 60 μm2, and the confinement loss is as low as <0.025 dB/km at 1550 nm. While choosing suitable structure parameters, an ultra dispersion-flattened MF within a broadband from1000 nm to 1900 nm can be achieved. The dispersion fluctuation is 0.6–1.0 ps/(nm·km) in all S, C and L band.