Air-guiding photonic crystal fibers with modified honeycomb lattice

Air-guiding has been demonstrated in a modified honeycomb photonic crystal fiber. The confinement losses and dispersion properties are numerically investigated by means of the finite element method (FEM). A guided mode with more than 98% of power propagating in air has been found over a wavelength range of about 200 nm. By means of a proper design, confinement losses lower than 0.1 dB/Km at /spl lambda/ = 1.55 /spl mu/m can be obtained with ten cell rings and an air filling fraction of 74.4%.