Micromachining by CO2 laser ablation: Building blocks for a multiport integrated device

We report on the design and fabrication of complex microcomponents based on multimode optical interference, using a CO2 laser ablation technique. Mode confinement, power division and losses are assessed. Power splitters show a good balance in the intensity division but beam combiners exhibit a variation in output power. The devices are compact and show a low sensitivity to imperfections in the fabrication process. The results demonstrate the technique's potential to develop multiport integrated circuits.