Silicon Photonics: Fundamentals and Devices

1.5 Data Network

While long-haul optical communication systems work at 1.55 µm, to exploit the minimum attenuation in the fiber, local area networks span smaller distance and area. In this case, working at other wavelengths, at the cost of higher attenuation of signals, may be of advantage due to the availability of cheap components. A possible system employs GaAs-based lasers at around 800 nm, at which wavelength Si photodetectors and other electronic circuits would offer a low-cost solution. If, in addition, Si emitters are available, further reduction in cost is highly expected.

A large part of data communication network is anchored to servers and desktop computers that utilize Si devices. The large potential volume of the market and the competition with copper cables will necessitate more use of inexpensive optical fibers. Si-based photonic components will offer the cheapest solution to the network.