Fabrication and characterisation of direct laser-written multimode polymer waveguides with out-of-plane turning mirrors

This paper describes work on the development of a two-level lightwave circuit containing multimode polymer waveguides with 45° out-of-plane turning mirrors to communicate between the layers. The polymer waveguides and mirror structures are produced using a direct laser-writing system. The system is based on a He-Cd (325 nm) UV laser and a vertically mounted slotted base-plate which is used to align the polarising, routing and focussing optics that guide and focus three beams (at normal and ±45° angles) onto a computer controlled XY translation stage.