Abstract
The nonlinear dynamics of a semiconductor laser (slave laser) injected by optical pulses with high repetition rate are investigated experimentally. The pulses for injection are generated from a laser (master laser) subjected to either an optoelectronic feedback or an optical feedback. The repetition rates of the pulses are controlled by varying the delay time and the feedback strength of the feedback loop. By injecting the repetitive optical pulses of different intensities and repetition frequencies into another laser (slave laser), rich dynamical states including regular pulsations, frequency beatings, and chaotic pulsations are observed. Moreover, frequency-locked states with different winding number, the ratio of the main pulsation frequency of the slave laser and the repetition frequency of the injected pulses, are also found. Compared to a laser subject to a sine modulated optical injection, the linewidths of the high-order microwave components in the output spectrum of the slave laser are substantially narrower for the laser under repetitive optical pulse injection.