Thanks to its important features in the field of integrated electronic circuits and CMOS processes, Silicon is one of the most used semiconductor in electronic industry. Actually, research is moving in the direction of using this material also for photonic application, trying to integrate photonic devices over semiconductor platforms, with the purpose to improve integrated circuits performances, for example increasing transmission velocity. Silicon Photonics studies how efficiently embed photonic components in silicon integrated circuits. The main drawback of using Silicon-based technology in photonic circuits, is that Silicon is and indirect band-gap semiconductor, this means that is not perfectly suitable to fabricate active optical devices, like lasers, since during recombination processes there is not energy-momentum conservation.