Silicon photonics is the study and application of photonics|photonic systems which use silicon as an optical medium. The silicon is usually patterned with nanoscale|sub-micrometre precision, into microphotonics|microphotonic components.
The propagation of light through silicon devices is governed by a range of nonlinear optics|nonlinear optical phenomena including the Kerr effect, the Raman effect, two photon absorption and interactions between photons and free charge carriers. The presence of nonlinearity is of fundamental importance, as it enables light to interact with light, thus permitting applications such as wavelength conversion and all-optical signal routing, in addition to the passive transmission of light.
Silicon waveguides are also of great academic interest, due to their ability to support exotic nonlinear optical phenomena such as Soliton (optics)|soliton propagation.