Semiconductor laser and optical communication system using the same

Abstract

A red semiconductor laser including a first type GaAs substrate having a set of layers sequentially formed on the substrate, which includes at least: a first conductivity type AlInGaP clad layer; an AlInGaP lower optical guide layer; a quantum well active layer made of GaInP or AlInGaP; an AlInGaP upper optical guide layer; a second conductivity type AlInGaP first upper clad layer including a non-doped region formed on the side of the upper clad layer facing the upper optical guide layer; a second conductivity type GaInP heterobuffer layer; and a second conductivity type GaAs cap layer. The second conductivity type carrier concentration at the interface between the first upper clad layer and upper optical guide layer is kept at a value which is less than or equal to 4×1016 cm−3.

Dependencies are inferred from the claim text.