Mid-Infrared Silicon Photonics for Communications

The mid-infrared wavelength region is important for a number of application areas, two of which are optical fibre and free space communications. Silicon photonics can provide inexpensive photonic chips for such applications due to excellent electronic and photonic properties. In this paper, the realisation of active silicon and germanium photonic devices for the mid-infrared spectral region are given. High speed Si depletion type modulators, Si and Ge injection modulators operating at wavelengths up to 8 micrometers, and high speed Si detectors are presented. These devices are integrated with drivers and amplifiers and show very good performance, e.g. data rate in excess of 20 Gb/s.