Patent ID: 7915634

Claim:
A laser diode epitaxial wafer, comprising: an n-type GaAs substrate; an n-type cladding layer formed on the n-type GaAs substrate; an active layer formed on the n-type cladding layer; and a p-type cladding layer formed on the active layer, wherein the n-type cladding layer, the active layer, and the p-type cladding layer each comprise an AlGaInP-based material and have a double-hetero structure, wherein the p-type cladding layer comprises a p-type impurity consisting of carbon, wherein the p-type cladding layer has a carrier concentration between 8.0×10 17 cm −3 and 1.5×10 18 cm −3 , wherein the p-type cladding layer comprises a carrier concentration distribution in a depth direction thereof of within ±5%, wherein the p-type cladding layer has a thickness of 1.5 μm or more, and wherein the active layer comprises an undoped active layer and a carrier concentration of not more than 7.0×10 16 cm −3 .