Patent ID: 8189638

Claim:
A laser diode device comprising: a substrate composed of GaN; an n-type cladding layer and a p-type cladding layer that are provided on one side of the substrate and that are composed of nitride Group III-V compound semiconductor containing at least gallium (Ga) out of Group 3B elements and at least nitrogen (N) out of Group 5B elements, and contain aluminum (Al) at least in part; an active layer that is provided between the n-type cladding layer and the p-type cladding layer and that is composed of nitride Group III-V compound semiconductor containing at least indium (In) and gallium (Ga) out of Group 3B elements and at least nitrogen (N) out of Group 5B elements; and a co-doped layer that is provided between the substrate and the n-type cladding layer and that is composed of nitride Group III-V compound semiconductor containing at least gallium (Ga) out of Group 3B elements and at least nitrogen (N) out of Group 5B elements, and is co-doped with one of silicon (Si) and germanium (Ge) as impurity working as a donor and one of magnesium (Mg) and zinc (Zn) as impurity working as an acceptor, wherein, the co-doped layer is provided adjacent to the n-type cladding layer without an intervening layer in-between, and has a narrower forbidden band than that of the n-type cladding layer.