Formation of InAsP layer on corrugated InP substrate by MOVPE for buried grating of DFB lasers

Characteristics of the InAsP layer formed on a corrugated InP substrate by a mass-transport mechanism have been investigated for use as the buried grating of distributed feedback (DFB) lasers, The size of the InAsP layer can be controlled by the height of the corrugation, and the arsenic composition in the InAsP layer can be controlled by the AsH/sub 3/ partial pressure. The results of TEM, EDS and PL show that InP is suitable as the buffer layer between the InAsP layer and MQW active layer. Fabricated 1.3 /spl mu/m DFB lasers which have an InAsP layer as an absorptive grating have shown low threshold current and high slope efficiency from -40-+85/spl deg/C, and high reliability has been demonstrated.