Design of single-mode large-mode area bandgap fibre with microstructured-core

Tailoring the modal characteristics of all-solid photonic bandgap fibre by the inclusion of low-index rods in the fibre core is investigated. By lowering the core index of the fibre, the high-order modes in the fibre can be shifted to the border of the bandgap, as a result, single-mode operation in large-mode area bandgap fibre can be realized without bending the fibre. In addition, large-mode area and single-mode operation in the all-solid microstructured-core bandgap fibre can be achieved by bending the fibre at a wide bending radius range.