Low threshold current density InGaAsP/InP lasers grown in a vertical liquid phase epitaxial system

Abstract

Threshold current density of InGaAsP/InP double heterostructure lasers made from crystals grown in a vertical liquid phase epitaxial system and emitting at 1.3 μm is given versus active layer thickness. Extremely low normalized threshold current density is observed Jth/d∼1.6kA/cm2 μm, which represents a considerable improvement over state of the art. The lowest threshold density among 80 lasers studied is 1 kA/cm2. Good uniformity over each wafer is found along with consistency of the results among different experiments. Since standard preparation and fabrication techniques are used in this work, it is assumed that favorable thermal conditions existing in the vertical liquid phase epitaxial system might be responsible for these promising results.