Ultra-flattened dispersion photonic crystal fibre

A simple structure of octagonal photonic crystal fibre (O-PCF) for ultra-flattened chromatic dispersion and extremely low confinement losses is presented. It has been demonstrated that a four-ring O-PCF can operate a single mode in a 390 nm wavelength range with ultra- flattened chromatic dispersion and a very low confinement loss less than 0.001 dB/km.