Low dimensional silicon to enable silicon photonics

In this chapter we will review the photonic applications of nanos-tructured silicon. As we change the dimensionality of silicon very fasci-nating and new optical properties of the material appear. In particular, light emission starts to be a very efficient process in nanostructured silicon and light emitting diodes with efficiency in excess of 1 % have been fabricated. Optical amplification has been also observed when silicon nanocrystals are embed into a dielectric matrix. In addition to electronic property variations, nanostructured silicon can be also used as a nanodielectric material. Some examples will be discussed where photonic Bloch oscillations, photonic Zener tunnelling and high quality microcavities are demonstrated.