Mechanism and Optimum Demodulation Scheme for Frequency-Modulated FeedbackSustained Pulsations in Laser Diodes

摘要

The operation regimes and dynamic properties of semiconductor laser diodes aresignificantly affected by external feedback. Investigation of the dynamics of Self-Sustained Pulsation (SSP) in the semiconductor laser diodes with optoelectronic feedback is presented. The Laser Diode (LD) is assumed to be a noiseless two section Fabry-Perot laser diode with linear gain in both sections. The feedback is assumed to consist of a photodetector and wide band and band pass microwave amplifier. For a certain range of the laser diode and feedback parameters the system undergoes high frequency (about 1 GHz) oscillations resulting from structural instability in system dynamics. Frequency, amplitude and other parameters of Self-Sustained Pulsation are electrically tunable. The system dynamics are investigated from the standpoint of stability analysis as well as direct numerical simulation. The stability analysis performed shows that for certain laser diode and feedback operating parameters, the feedback laser diode system exhibits an instability which results in Self-Sustained Pulsation.