Large-mode-area index-guiding holey fibers with ultra-low ultra-flattened dispersion using a novel hollow-ring defect structure

A novel silica index guiding holey fiber (IGHF) design that utilizes a new defect core structure composed of 2-layered high index rings with a triangular lattice structure is proposed in order to control the chromatic dispersion and the mode area. The proposed IGHF shows unique modal properties, such as nearly zero flattened dispersion over a wide spectral range with a low dispersion slope of less than 1.10 ^-3 ps/(km.nm ²). The numerical results shows that it is possible to design a novel IGHF with an ultra-flattened dispersion of 0 ± 0.5 ps/(km.nm) from wavelengths of 1.36 μm to 1.75 μm and for an effective mode area as large as 100 μm ² in the same spectral range. Moreover, with an adiabatic mode transformation, the proposed fiber can be effectively connected to a conventional optical fiber with a low splicing loss of less than 0.01 dB.