| 摘要 |
A high beam quality (a beam quality factor (M2) less than 1) is produced from a semiconductor laser element. A diffraction grating (6ba) in a diffraction-grating layer (6) is provided on a p-side surface (6a) of said diffraction-grating layer (6) and is located within a principal plane (2a). The index of refraction of the diffraction-grating layer (6) varies periodically across the principal plane (2a) within the diffraction grating (6ba). The diffraction grating (6ba) is provided with a plurality of holes (6b). Said holes (6b) are provided in the aforementioned p-side surface (6a), are arrayed in a square grid (R3) so as to exhibit translational symmetry, and are all the same size and shape. The holes (6b) correspond to the grid points of the diffraction grating (6ba) and are triangular-prism-shaped, and the bottom (6c) of each hole (6b) is substantially right-triangular-shaped. |
