Integrated in‐plane mirror and multimode waveguide fabrication using 248 nm excimer laser ablation for optical interconnects on PCBs

Purpose The purpose of this paper is to present the need, and a potential solution, for in‐plane routing of optical signals for optical‐enabled circuit boards. Design/methodology/approach Multimode waveguides and integrated 45° in‐plane mirror structures were made in a low loss acrylate‐based photopolymer using excimer laser ablation. The fabrication of multimode waveguides and mirrors was carried out in a single laser system which minimised alignment issues. Findings It was established that in‐plane mirror fabrication using laser ablation can be achieved and can potentially be used to define mirrors in waveguides made by other methods such as photolithography. Research limitations/implications While the concept (integrated in‐plane mirror) was demonstrated, the viability of its deployment will depend on the results of optical loss measurements for which further research is required. Originality/value The paper gives an overview of the design concept and fabrication steps for an in‐plane embedded mirror.