Design of ZBLAN photonic crystal fiber with nearly zero ultra-flattened chromatic dispersion for supercontinuum generation

In this paper, we present and numerically investigate Supercontinuum Generation (SCG) in ZBLAN circular lattice photonic crystal fiber with nearly zero ultra-flattened chromatic dispersion. The fiber dispersion properties are controlled by selectively liquid-filled and reduced air holes. The structure parameters have been optimized by using the fully vectorial finite-difference frequency-domain (FDFD) method combined with the perfectly matched layers (PML) boundary condition. Results indicate that a nearly zero ultra-flattened chromatic dispersion is obtained over a broad band of 300 nm centered around 1.55 μm with high nonlinearity and low confinement loss. Furthermore, SCG at 1.55 μm is demonstrated with the optimized design. By using a 3.2 kW peak power 100 fs input secant-hyperbolic pulse, a symmetrical and relatively flat supercontinuum spectrum spanning 700 nm in the range of 1200-1900 nm is successfully generated.