Effect of linear gain saturation on small-signal dynamics of MQW DFB lasers

The linear gain saturation effect is shown to be important in determining the dynamics of multiple-quantum-well (MQW) distributed-feedback (DFB) lasers. A more realistic logarithmic dependence of material gain on carrier density is assumed in a comprehensive MQW DFB laser model. It is found through simulation that because of the linear gain saturation, the interplay between modal gain and differential gain leads to an optimal kappa L for maximum small-signal modulation bandwidth in lambda /4-shifted MQW DFB lasers.<
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