Enhanced AM and FM modulation response of complex coupled DFB lasers

Significant improvements in the small AM bandwidth and FM efficiency of a DFB laser are obtained by introducing a carrier dependent complex coupling coefficient. A simulation using a large-signal dynamic model shows that the 3-dB cutoff frequencies for AM can be increased by factors of three by having the index and gain coefficients in antiphase. In contrast, the efficiency of FM, at low frequencies, can be similarly improved if the index and gain coupling are in phase.<
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