Ultrahigh-frequency self-pulsations under gain-switching modulation in 1.5-/spl mu/m dynamical single-mode monolithic compound-cavity semiconductor lasers: Experiment and theory

The generation of 50-130-GHz high-frequency self-pulsations in ultrafast gain-switched InGaAs-InGaAsP dynamical single-mode monolithic compound-cavity lasers is studied in this paper. With various cavity lengths, the dependence of the pulsation frequency on the length of the respective cavity is shown and analyzed in detail. To explain the observed phenomena, a dynamic theory of the semiconductor laser amplifier is described which takes into account the coherent time-dependent amplification, shortening, and reflection of an incident picosecond optical pulse in the gain-switched amplifier. With the presented model, the theoretical simulation results agree well with the experimental observations.