Wavelength conversion based on degenerate four-wave mixing (FWM) was demonstrated and compared between silicon nanowire and microring resonator (MRR). 15 dB enhancement of conversion efficiency (CE) with relatively low input pump power (5 mW) was achieved experimentally in an MRR. The impacts of bus waveguide length and propagation loss were theoretically analyzed under the effect of nonlinear loss.FosterMA, Turner A C, Sharping J E, Schmidt B S, Lipson M, Gaeta A L. Broad-band optical parametric gain on a silicon photonic chip. Nature, 2006, 441(7096): 960–963