Observation of Bifurcation to Chaos in an All-Optical Bistable System

The bifurcations to periodic and chaotic states in an all-optical bistable system proposed by Ikeda et al. have been observed. A single-mode optical fiber was used as a nonlinear medium in a ring cavity. The incident beam was the second harmonic of a pulse train from an actively mode-locked and $Q$-switched yttrium-aluminum-garnet laser whose cavity length was equal to one-half that of the ring cavity. The bifurcation to period-two state was clearly observed at a certain level of the incident power, and further increase in power resulted in a chaotic state.