Demonstration of an MT-compatible connectorisation of a laser-ablated optical interconnection on a printed circuit board

Integration of optical interconnections on a Printed Circuit Board (PCB) is very challenging, as compatibility should be maintained with standard PCB manufacturing technology. This paper describes the use of laser ablation, a technique already used in PCB manufacturing for drilling microvia's, as a suitable technique for the fabrication of multimode polymer waveguides, micromirrors, alignment features and microlenses. A frequency tripled Nd-YAG laser and a KrF excimer laser are used, both mounted on the same stage, resulting in a very high alignment accuracy. We demonstrate a parallel optical link over about 5 cm long PCB integrated waveguides, fully connectorised using a standard MT-based connector. This proves that laser ablation can be a key technology in optical board manufacturing to reach the stringent coupling tolerances.