Assorted core air-clad fibre

Summary form only given. We demonstrate a new technique for fabricating an optical fibre with an array of essentially air-clad cores of different dimensions. This relies on techniques developed in the production of holey optical fibres, which are typically fabricated from stacking silica tubes around a solid silica rod. When thin walled capillaries are stacked and drawn to fibre, additional cores can form at regions where capillaries meet with differing sizes resulting from variations in tube thickness and diameter. Here we present such an assorted core fibre which contains independently addressable small cores of different dimensions.