Semiconductor laser coupled to a finite-response time phase-conjugate mirror

Most of the previous treatments of semiconductor lasers subject to optical feedback from a phase-conjugate mirror (PCM) have assumed the PCM responds instantaneously. Furthermore, the mechanism responsible for phase conjugation does not usually enter into the analysis. In this paper are derived the time-dependent reflectivity from a PCM created through non-degenerate four-wave mixing. The resulting laser dynamics are compared to the case of the ideal PCM, as a function of PCM mirror interaction depth, distance to the PCM, and laser current. The time-responsive PCM tends to suppress otherwise chaotic output and produces power pulses whose frequency is tunable by varying laser current or PCM reflectivity.