Spectral aspect of degradation in 1.55 mu m long-cavity MQW DFB lasers

Degradation behaviors, particularly for the increase in spectral linewidth and FM efficiency, in 1.55 mu m long-cavity MQW (multiple quantum well) DFB (distributed feedback) lasers, with a spectral linewidth of around 1 MHz, are presented from the viewpoint of coherent system application. Through the clarification of the behaviors, it is shown that highly coherent lasers are sufficiently durable in coherent transmission systems.<
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