Analysis of threshold temperature characteristics for InGaAsP/InP double heterojunction lasers

Abstract

This paper presents a theoretical study of threshold temperature characteristics of InGaAsP/InP double heterojunction lasers, from the standpoint of carrier leakage from the quaternary active region into the InP confining layers. The leakage carrier concentration flowing beyond the heterobarrier of the InP confining layer is evaluated through an analysis of heterojunction energy-band structure. Analytical results indicate that, for an emission wavelength of 1.3 μm, the sharp increase in threshold current near room temperature is caused by carrier leakage. The contribution of carrier leakage is also discussed in relation to various wavelength InGaAsP lasers.