Highly nondegenerate four-wave mixing in uniform and /spl lambda//4-shifted DFB lasers

A theoretical investigation of highly nondegenerate four-wave mixing (HNDFWM) in uniform and quarter-waveshifted distributed feedback (DFB) lasers in the weak injection regime has been performed using a numerical analysis of the coupled-wave equations. The effects of carrier spatial and spectral hole burning, carrier heating, and longitudinally variable pump field above the laser threshold are included. Pump-probe detunings up to 1.5 THz are investigated. It is found that, for small and moderate DFB coupling coefficients, the conjugate wave can be generated in a bandwidth of /spl sim/1 THz with an efficiency of -20 dB or more, compared to the injected probe power.