On the route towards a monolithically integrated silicon photonics

Speed and complexity of integrated circuits are more and more increasing as integrated technology advances. The combination of ever-increasing chip size and decreasing feature size, however, has already raised its fundamental bottleneck in terms of speed, packaging, fanout, and power dissipation. Optical interconnects become more and more essential. Till now, the reliability and compatibility of many optical interconnect systems are quite far from a real integrated system and are based on hybrid approaches which make the fabrication difficult and costly. In the last years a big research effort was aimed to render Si an optical active materials so that it can be turned from an electronic material to a photonic material. In this paper the state of the art of the research carried out at Trento on the main "building block" towards a monolithically integrated photonics based on silicon is presented: the studies on optical gain in silicon nanocrystals to realize a light source, the Si laser.