Observation of Raman emission in silicon waveguides at 1.54 microm

We report the first measurements of spontaneous Raman scattering from silicon waveguides. Using a 1.43 m pump, both forward and backward scattering were measured at 1.54 m from Silicon-On-Insulator (SOI) waveguides. From the dependence of the Stokes power vs. pump power, we extract a value of (4.1 +/- 2.5) x 10-7 cm-1 Sr-1 for the Raman scattering efficiency. The results suggest that a silicon optical amplifier is within reach. The strong optical confinement in silicon waveguides is an attractive property as it lowers the pump power required for the onset of Raman scattering. The SiGe material system is also discussed.