1.55 μmHIGH SPEED PARTLY GAIN-COUPLED DFB LASERS WITH PERIODICALLY ETCHED STRAINED-LAYER QUANTUM WELLS

摘要

The high speed performance of partly gain-coupled (GC) DFB lasers consisting of periodically etched strained-layer quantum wells (QW's) is reviewed with comparisons to the equivalent index-coupled (IC) DFB lasers with the same active layers. It is shown that the GC DFB laser has a -3 dB modulation bandwidth of 22 GHz at 10 mW with a stable single mode oscillation at the longer side of the Bragg stop-band due to in-phase gain coupling. A theoretical analysis is also presented based on the local-normal-mode transfer-matrix laser model which takes into account both the longitudinal distribution of laser parameters and carrier transport effects. The mechanism for high modulation bandwidth of the GC D FB laser is attributed to a higher differential gain due to a reduced carrier transport time which is provided by an efficient carrier injection from the longitudinal etched interface of the QW's.