Fabrication and transmission experiments of distributed feedback laser modules for 2.5 Gb s-1 optical transmission systems

A distributed feedback (DFB) laser module has been developed for 2.5 Gbs^-1 optical transmission systems. The DFB laser has a multiple-quantum-well (MQW) active layer and a planar buried heterostructure (PBH) for a low threshold current and stable singlemode operation with low chirping. A PBH DFB laser module with a single-mode fibre pigtail and an optical isolator was designed and fabricated by employing a single lens and a laser welding method. The fabricated MQW PBH DFB laser module is shown to be a suitable light source for 2.5 Gb s^-1 optical transmission systems with a minimum received power of-33 dBm after 47 km conventional optical fibre transmission.