Spectral linewidth rebroadening in MQW-DFB LDs caused by spontaneous emission noise in SCH/barrier layers

A new theory is proposed to explain spectral linewidth rebroadening in MQW-DFB LDs. This is based on the idea that spontaneous emission recombination in the SCH and barrier layers may cause excess spectral linewidth broadening. Theoretical and experimental studies show that excess spectral linewidth broadening is proportional to the recombination current in the SCH/barrier layers. This current increases monotonically as output power increases.<
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