Intermittent bursts in a directly modulated laser diode

摘要

Based on a rate equation description of a directly modulated laserndiode, we investigate the origin of intermittent bursts that appear innthe output power of the device. Sudden drops in the maximum amplitude ofnthe laser's output characterize this behavior, found in the periodndoubling sequence that appears when the modulation index varies. Fromnthe investigation of this behavior the paper reveals the cause for thenextreme sensitivity to noise of modulated laser diodes. Usingnbifurcation theory techniques, we explain how the unstable periodicnsolutions and the intrinsic noise of the device play a key role in thenmechanism giving rise to these bursts. The paper shows that thenmechanism is composed of two fundamental stages, which have beennreferred to as capture and reinjection. As we clarify the origin of thentwo stages, the different time scales involved in each one are alsonidentified. From this analysis, we can conclude that the intermittentnbursts are a characteristic signature of the process by which the lasernstochastic dynamics progressively embeds one of the saddle cycles as thenmodulation index is varied