Efficient wavelength conversion based on quasi-phase-matched four-wave mixing in a silicon waveguide with a microring phase shifter

An all-pass microring resonator is utilized in silicon waveguides to adjust the relative phase relationship among the involved waves in the degenerated four-wave mixing (FWM). By using the microring resonator as a phase shifter, the phase matching can be ameliorated, and the conversion efficiency can be enhanced effectively. The influences of key factors including the coupling strength of the ring resonator, and the nonlinear loss introduced by two-photon absorption and free carrier absorption, on the improvement of conversion efficiency are discussed. By properly selecting the parameters, the spectra of conversion efficiency are flattened in the wavelength range of 10 nm. Since the ring resonator has a periodic response spectrum and tunable resonant wavelength, the FWM with a microring phase shifter provides an efficient approach to wavelength conversion in silicon waveguides. (C) 2013 Optical Society of America