Demonstration of Ultra-Flattened Dispersion Low Confinement Loss in Square Lattice Structure Photonic Crystal Fibers

摘要

A simple structure of photonic crystal fibers (PCF) with both a nearly zero ultra-flattened dispersion and low confinement loss has been proposed and numerically simulated by using an efficient full vector finite element method (FV-FEM) with anisotropic perfectly matched layers for accurate modeling of PCF. This type of fiber is composed of a solid silica core and a cladding with square lattice uniform elliptical air-holes along the fiber length. The optimized result has been obtained by adjusting the design parameter of the proposed fiber, which has a total dispersion as low as ±2.5 ps·km~(-1) nm~(-1) over an ultra-broad wavelength range from 1.43 to 1.8 μm, and the corresponding confinement loss is 0.016 dB·km~(-1) at wavelength of 1.55 μm, and in addition the relatively small effective mode area of 3.6 μm~2 is obtained at the same wavelength, which will induce higher non-linearity coefficient is close 42 W~(-1) · km~(-1). The proposed PCF have the main advantages including the simple structured parameter, the ultra-flattened dispersion feature, the low confinement loss as well as the small effective mode area at the mean while, which will make it suitable as a chromatic dispersion controller, a dispersion compensator, or a candidate for the nonlinear optical application in the four-wave mixing.