| 摘要 |
PURPOSE:To emit a laser light having excellent directivity by effectively emitting a laser oscillation light to an upper portion by enhancing both end reflectivities of a distributed feedback type laser containing a diffraction grating and opening a window for an upper electrode, and increasing an emitting light spot. CONSTITUTION:In a semiconductor laser, a resonator is composed in a direction a-a', metal reflection films 3 are bonded to both ends through insulator films 2 in a high reflection structure to suppress the radiation of a laser light from the direction of the resonator toward the exterior, and a light diffracted upward is effectively emitted as by an arrow by a secondary diffraction grating 1. The laser light diffracted upward is emitted from the electrode of the structure having an electrode metal at the center as 4, i.e., from the surface of the electrode with a light emitting window 4a upward. Thus, the emitting light spot size becomes an active layer width X a resonator length to be very large as a laser light emitting structure to obtain an extremely small beam spreading angle. |
