Is silicon photonics a new technology?
No. Photonics on silicon has been suggested since the 1970s. However, previous light-beam devices on silicon were excessively large (by microchip standards) or have required very high-powers for operation. It is only in the last few years, however, with the advancement of fabrication techniques that sub-micron-size photonic structures have been realized. This together with recent demonstrations of efficient fiber to waveguide couplers have enabled the demonstration of a large number of ultra-compact photonic components with very low loss. The challenges of using silicon as a photonic material are its high propagation losses, low electro-optic coefficient and low light emission efficiency, and the difficulty in fiber-to-waveguide coupling. The high confinement nature of the recently demonstrated compact photonic structures have enabled some of the traditional limitations of Si photonics to be overcome.
