Exploiting the strong optical confinement and the large Raman gain in the material, the first optical amplifiers and lasers in silicon have been demonstrated. Wavelength conversion, between the technologically important wavelength bands of 1,300 and 1,500 nm, has been demonstrated through Raman-enabled four-wave mixing. Carrier lifetime is the single most important parameter affecting the performance of silicon Raman devices. The desired reduction in lifetime is attained by reducing the lateral dimensions of the optical waveguide and actively removing the carriers with a reverse-biased diode. An integrated diode also offers the ability to electrically modulate the optical gain. The rigid Raman spectrum of silicon can be engineered by using germanium-silicon alloys and superlattices.
Boyraz, O. (2006). Silicon Raman laser, amplifier, and wavelength converter. Springer Series in Optical Sciences, 119. https://doi.org/10.1007/978-3-540-28912-8_3