Anti-Stokes Raman conversion in silicon waveguides

The first observation of parametric down-conversion in silicon is reported. Conversion from 1542.3 nm to 1328.8 nm is achieved using a CW pump laser at 1427 nm. The conversion occurs via Coherent Anti-Stokes Raman Scattering ( CARS) in which two pump photons and one Stokes photon couple through a zone-center optical phonon to an anti-Stokes photon. The maximum measured Stokes/anti-Stokes power conversion efficiency is 1 x 10(-5). The value depends on the effective pump power, the Stimulated Raman Scattering (SRS) coefficient of bulk silicon, and waveguide dispersion. It is shown that the power conversion efficiency is a strong function of phase mismatch inside the waveguide. (C) 2003 Optical Society of America.