Integration of multimode waveguides and micromirror couplers in printed circuit boards using laser ablation

Integration of optical interconnections on a Printed Circuit Board (PCB) is very challenging, as it should remain compatible with existing PCB manufacturing technology. We will describe the use of laser ablation, already used in PCB manufacturing for microvia’s, as a suitable technique for the fabrication of multimode waveguides and micromirrors to provide optical coupling. The focus is on ablation of waveguides using a frequency tripled Nd-YAG laser and on ablation of 45 facets using a KrF excimer laser. It is shown that these structures can be defined in one single processing step, resulting in a very accurate alignment.