Single-mode photonic crystal fiber with low bending loss and Aeff of > 200 μm2 for ultra high-speed WDM transmission

We propose photonic crystal fiber with W-shaped effective index profile to achieve the largest A<sub>eff</sub> for telecommunication use. We realized a 220-μm<sup>2</sup> A<sub>eff</sub> with a cut-off wavelength and bending loss compatible with ITU-T recommendation G.655.