Silicon is the electronic material per excellence. Integration and economy of scale are the two keys ingredients for the silicon technological success. Silicon has a band-gap of 1.12 eV, which is ideal for room temperature operation, and an oxide (SiO2), which allows the processing flexibility to place today more than 10 devices on a single chip. The continuous improvements of silicon technology have made possible to grow routinely 200 mm single silicon crystals at low cost, and even larger crystals are now under development. The high integration levels reached by the silicon microelectronic industry have permitted high-speed device performances and unprecedented interconnection levels [1]. However, today the required interconnections between devices are sufficient to cause critical propagation delays, over heating and information latency. To overcome this interconnection bottleneck is together the main motivation and opportunity for silicon Microphotonics, where attempts to combine photonics and electronic components on a single Si chip or wafer are strongly pursued. In addition, photonics aims to combine the power of silicon microelectronics with the advantages of photonics. In this way it is expected that the continuous increase of chip performances predicted by Moore’s law can be ultimately faced.Silicon Microphotonics has boomed in the recent years [2-5]. Several silicon photonics devices have been demonstrated, eg, silicon based optical waveguides with ex-tremely low losses and small curvature radii [3], tunable optical filters, fast switches (ns)[6] and fast optical modulators (GHz)[7], fast CMOS photodetectors [8], integrated Ge …