Monolithically integrated directly modulated DFB laser array with MMI coupler for 100GBASE-LR4 application

We developed the first 1.3-µm, 4×25-Gbit/s directly modulated DFB laser array monolithically integrated with an MMI coupler suitable for 100GBASE-LR4 application. Error-free operation was achieved for a 30-km SMF transmission when modulating four DMLs simultaneously.