Multi-channel wavelength conversion using Four-Wave Mixing in Semiconductor Ring Lasers

In this contribution, the four-wave mixing (FWM) properties shown by semiconductor ring lasers (SRLs) were exploited to propose a new technique to perform wavelength conversion of multiple channels simultaneously with only one SRL. Numerical investigation were made of the dynamics of the SRL via a semi-classical Traveling Wave Model (TWM), describing the two counter-propagating electric fields, polarizations and carrier dynamics, that allows description of spatial effects and multimode operation naturally in time-scales longer than 1 ps. Simulations show that biasing the SRL in the unidirectional regime and injecting light pulses in the co-propagating direction of emission of the SRL at a wavelength detuned from the lasing mode enable conversion of the wavelength of the injected signal via FWM. However, it should be noticed that this process can present some problems, e.g. locking at the injected wavelength if the intensity of the injected signal is sufficiently higher, or directional switching via non-linear processes between the FWM fields and the material that can lead to unexpected behavior.