Semiconductor laser diode

Provided is a semiconductor laser diode, including a GaAs/In P substrate and a multi-layer structure on the GaAs/InP substrate. The multi-layer structure includes a lower epitaxial region, an active region and an upper epitaxial region. The active region comprises a first active layer, an epitaxial region and a second active layer, the epitaxial region is disposed between the first active layer and the second active layer, the first active layer comprises one or more quantum well structures or one or more quantum dot structures, and the second active layer comprises one or more quantum well structures or one or more quantum dot structures. the epitaxial region further comprises a tunnel junction and at least one carrier confinement layer, at least one carrier confinement layer is disposed between the tunnel junction and the first active layer or between the tunnel junction and the second active layer such that the at least one carrier confinement layer blocks electrons or holes, and no electrons or holes are able to reach the tunnel junction.