1.3 μm Quantum Dot Laser in coupled-cavity-injection-grating design with bandwidth of 20 GHz under direct modulation

Using a multi section laser in coupled cavity injection grating design based on 1.3 microm InGaAs/GaAs quantum dot (QD) active region we were able to enhance the 3 dB modulation bandwidth well beyond the inherent material modulation bandwidth. The material bandwidth was determined by measurements on distributed feedback (DFB) devices to approximately 8 GHz. The special multisectional design allows interaction between the lasing mode and a second mode used as catalyst and enables a high resonance frequency of the device. Based on active QD material this approach allowed us to reach a cut off frequency of 20 GHz in the small signal response of the device.