Group-III nitride semiconductor laser device

摘要

A group-III nitride semiconductor laser device comprises: a laser structure including a semiconductor region and a support base having a semipolar primary surface of group-III nitride semiconductor; a first reflective layer, provided on a first facet of the region, for a lasing cavity of the laser device; and a second reflective layer, provided on a second facet of the region, for the lasing cavity. The laser structure includes a laser waveguide extending along the semipolar surface. A c+ axis vector indicating a <0001> axial direction of the base tilts toward an m-axis of the group-III nitride semiconductor at an angle of not less than 63 degrees and less than 80 degrees with respect to a vector indicating a direction of an axis normal to the semipolar surface. The first reflective layer has a reflectance of less than 60% in a wavelength range of 525 to 545 nm.

主权项

1. A group-III nitride semiconductor laser device comprising:
a laser structure including a support base and a semiconductor region, the support base including a group-III nitride semiconductor and having a semipolar primary surface, and the semiconductor region being provided on the semipolar primary surface of the support base; a first reflective layer for a lasing cavity of the group-III nitride semiconductor laser device, the first reflective layer being provided on a first end face of the semiconductor region; and a second reflective layer for the lasing cavity of the group-III nitride semiconductor laser device, the second reflective layer being provided on a second end face of the semiconductor region; the laser structure including a laser waveguide, the laser waveguide extending along the semipolar primary surface of the support base, the semiconductor region including an active layer, the active layer including a gallium nitride-based semiconductor layer, a c+ axis vector indicating a direction of a <0001> axis of the group-III nitride semiconductor of the support base, the c+ axis vector tilting at a tilt angle of not less than 63 degrees and less than 80 degrees with respect to a normal vector toward a crystal axis of an m-axis of the group-III nitride semiconductor, and the normal vector indicating a direction of an axis normal to the semipolar primary surface, the first reflective layer having a reflectance of less than 60% in a wavelength range of 525 to 545 nm, and the second reflective layer having a reflectance of 85% or more in the wavelength range of 525 to 545 nm, wherein, an end face of the support base and an end face of the semiconductor region are exposed at the first end face, and an end faces of the support base and an end faces of the semiconductor region are exposed at the second end face, and wherein, an angle defined by a reference plane and an end face of the active layer of the semiconductor region is in a range of (ALPHA−5) to (ALPHA+5) degrees on a first plane defined by a c-axis and the m-axis of the group-III nitride semiconductor, and the reference plane is orthogonal to an m-axis of the support base comprising the group-III nitride semiconductor.