Patent ID: 8483251

Claim:
A Group III nitride semiconductor laser diode comprising: a first conductivity type cladding layer provided on a primary surface of a semiconductor region, the semiconductor region comprising a first hexagonal Group III nitride semiconductor, and the first conductivity type cladding layer comprising a second hexagonal Group III nitride semiconductor; a first optical guiding layer provided on the first conductivity type cladding layer and comprising a third hexagonal Group III nitride semiconductor; a carrier blocking layer comprising a fourth hexagonal Group III nitride semiconductor; and an active layer provided between the first conductivity type cladding layer and the carrier blocking layer, the primary surface of the semiconductor region making an angle of not less than 10 degrees with respect to a reference plane perpendicular to a c-axis of the first hexagonal Group III nitride semiconductor, the first conductivity type cladding layer being lattice-relaxed on the primary surface of the semiconductor region, the first conductivity type cladding layer, the first optical guiding layer, the active layer, and the carrier blocking layer being arranged in a direction of a normal axis to the primary surface of the semiconductor region, the carrier blocking layer incorporating strain, the active layer comprising a semiconductor layer, and the semiconductor layer incorporating strain, the first optical guiding layer being lattice-relaxed on a primary surface of the first conductivity type cladding layer, and the primary surface of the semiconductor region having either of nonpolar character or semipolar character, wherein a direction of a c-axis in the first hexagonal Group III nitride semiconductor and a magnitude of a lattice constant d1 in the direction of the c-axis of the first hexagonal Group III nitride semiconductor are represented by a lattice vector LVC 1 , wherein a direction of a c-axis in the second hexagonal Group III nitride semiconductor and a magnitude of a lattice constant d 2 in the direction of the c-axis of the second hexagonal Group III nitride semiconductor are represented by a lattice vector LVC 2 , wherein the lattice vector LVC 1 includes a longitudinal component V 1 L in the direction of the normal axis and a transverse component V 1 T perpendicular to the longitudinal component, wherein the lattice vector LVC 2 includes a longitudinal component V 2 L in the direction of the normal axis and a transverse component V 2 T perpendicular to the longitudinal component, and wherein the transverse component V 1 T is different from the transverse component V 2 T .