Silicon Photonics

Silicon Photonics is no more an emerging research topic but is an actual technology with commercial products already available on the market. Quantum confinement of carriers or spatial localization of photons allows enhancing dramatically and widening the scope and potential of silicon photonics. The tremendous evolution of internet has urged the microelectronic and telecommunication industries to look at technologies to face the bandwidth, speed and power consumptions that internet requires. One technology which is emerging as a comprehensive solution to this is integrated photonics where complexity, reconfigurability and intelligence are thrusts. An ideal platform for such integration is to use the same material that has permitted the success of microelectronics in the last century, i.e., silicon. Silicon photonics is a technology where photonics devices are fabricated by using standard silicon technologies [1-4]. In this way it is possible to leverage on the capabilities of the silicon industry to mass manufacture cheap photonics devices. A key ingredient to achieve this goal is to exploit the high level of integration that parallel and planar processing allows. Still, integration in photonics is limited to few hundreds of different components in a single chip due to the complexity of integrated photonic circuits and to the needs of hybrid integration technologies to face all the different functionalities needed. Nowadays, all the different functions have been generated and integrated in silicon photonics by using silicon based materials or, when they are not possible, hybrid integration [4]. An example of this is the signal source which in silicon photonics is provided by a hybrid III-V on silicon laser.