40-Gb/s direct modulation in 1.3-μm InGaAlAs-MQW RWG DFB lasers

Direct modulation at 40 Gb/s in 1.3-μm InGaAlAs-MQW RWG DFB lasers was demonstrated. High differential gain of the InGaAlAs MQW active layer and short cavity length (100 m) of these lasers produce high bandwidth of 29 GHz and clear eye opening under 40-Gb/s operation at room temperature.