Numerical study on the waveguiding properties of photonic crystal fibers

The photonic band structure, mode field distribution, and leakage loss of different photonic crystal fibers are studied by the full vectorial plane wave expansion method and an extended beam propagation method. A comparison on the waveguiding mechanism is conducted among solid-core triangular-lattice PCF, air-core honeycomb PCF, and solid-core honeycomb PCF. For the latter two structures, which conduct light by the photonic bandgap effect, the advantages of down-doped solid-core honeycomb structure are demonstrated for its Gaussian-like mode field distribution and low leakage loss. A combined study on the leakage loss and band structure of solid-core honeycomb PCF has revealed the distinctive properties of photonic bandgap effect.