Highly nondegenerate four-wave mixing in a tunable dual-mode semiconductor laser

We present experimental investigations of highly nondegenerate four-wave mixing in a tunable dual-mode semiconductor laser. The fundamental interacting waves are two lasing modes selected in an external double Littman–Metcalf cavity configuration. We investigate the conversion efficiency depending on the detuning frequencies up to 1.2THz. We find that the newly generated waves are significantly enhanced due to the cavity resonances. Our investigations allow us to characterize and understand the dynamics of the simultaneous dual-mode operation in the semiconductor laser, which is attractive for the generation of continuous-wave THz radiation by photomixing.