| 摘要 |
<p>A semiconductor laser device comprises a semiconductor substrate of a first conductivity type (1) having a surface; a lower cladding layer of the first conductivity type (2), an active layer (3), and a first upper cladding layer of a second conductivity type (4) successively disposed on the surface of the semiconductor substrate of the first conductivity type (1); a first insulating film (5) disposed on the first upper cladding layer of the second conductivity type (4) and having a stripe-shaped opening; a ridge-striped second upper cladding layer of the second conductivity type (10) selectively grown in the stripe-shaped opening of the first insulating film (5); a second insulating film (13) disposed on the side surfaces of the second upper cladding layer of the second conductivity type (10) and the surface of the first insulating film (5); and a region of the active region corresponding to the ridge-striped second upper cladding layer of the second conductivity type (10) serving as a laser resonator having opposite laser resonator facets. In this device, the portions of the active layer (3) adjacent two opposed facets of the laser resonator include two opposed window regions (9) each having a higher band gap energy than the active region generating laser beam. Therefore, since the first upper cladding layer (4) except the portion beneath the ridge can have a certain thickness as intended, optical confinement in the horizontal direction can not be adversely affected. Moreover, since the same astigmatism as that of the conventional semiconductor laser device having no window structure can be obtained in the laser device, the semiconductor laser device capable of being used effectively for collecting lights in employing optical disks and optical fibers can be realized. <IMAGE> <IMAGE></p> |
