Raman-induced nonreciprocity in silicon photonic-crystal waveguides: benefits of slow light for optical isolators

The Raman-induced nonreciprocity of light propagation in photonic-crystal silicon waveguides is analysed. Although the Raman gain increases in the slow-light regime, the nonreciprocity is smaller. Thus, it is interesting that Raman-pumped optical isolators benefit from slow-light operation. Significant reductions in pump power and/or device length are found to be possible.