X-ray lithography of self aligning micro structures for fibre optic applications

Deep X-ray lithography provides a highly accurate, three dimensional, micro fabrication process and achieves minimum feature sizes of around 5 microns with sub-micron tolerances. It is believed that fibre optic applications will be among the first to benefit from deep X-ray lithography, because tight tolerances are required to minimise the insertion loss of a device. The use of deep micro structures with high aspect ratios permit optical fibres to be oriented to bulk optics and opto electronic components. In order to illustrate this, the design and fabrication of a prototype passive optical switch is reported. Integral to this device are self aligning structures capable of accurately positioning fibres relative to lenses and switching elements, thus removing the necessity for the active alignment of components