Multichannel Wavelength Conversion Using Four-Wave Mixing in Semiconductor Ring Lasers

We theoretically study all-optical simultaneous wavelength conversion of multiple channels by four-wave mixing in semiconductor ring lasers. Locking the semiconductor ring laser to a holding beam allows us to achieve large conversion efficiencies with good signal-to-noise ratio in several channels at multi-Gb/s bit rates. Cross-talk between signals, arising from the peculiar four-wave mixing cascade of modes in semiconductor ring lasers and their cross-gain saturation, is studied in detail. We show that it can be controlled by adjusting the intensity of the holding beam, the bias current of the laser, and the number, intensity, and wavelength of signals that one wants to convert.