Temperature characteristics of double-carrier-confinement (DCC) heterojunction InGaAsP(λ = 1.3 µm)/InP lasers

This paper reports on a detailed study of the oscillation characteristics of double-carrier-confinement (DCC) heterojunction InGaAsP( m)/InP lasers, with special emphasis on their temperature characteristics. In addition to conventional double-heterojunction lasers, these lasers have a p-InGaAsP second active layer sandwiched between the p-InP clad layers. The spectral characteristics below threshold were examined in order to verify electron leakage beyond the hetero-barrier of the p-InP thin clad layer, and to study the contribution of the second active layer to optical gain and laser action. Threshold temperature characteristics were also investigated through an analysis of the heterojunction energy band structure. The results indicate that emission from the second active layer is caused by electron leakage. In order to obtain high temperature stability for these lasers, it is essential that both the first and second active layers contribute to the optical gain spectrum and laser action.