Observation of Bistable Reflectivity of a Phase-Conjugated Signal through Intracavity Nearly Degenerate Four-Wave Mixing

Experimental results are presented regarding the generation and bistable behavior of a conjugated signal obtained through intracavity nearly degenerate four-wave mixing in a semiconductor laser amplifier injected with both pump ($\omega$) and probe ($\omega -\delta \omega$) frequencies. Conjugated reflectivities at $\omega +\delta \omega$ larger than 500% with 35% efficiency together with bistable behavior in the three signals (pump, probe, and conjugated) are reported.