| 摘要 |
PURPOSE:To miniaturize a semiconductor laser device by using a plane transparent plate set in parallel to a semiconductor substrate to correct the comparatively large astigmatism produced by a gain guide type semiconductor laser element. CONSTITUTION:The optical axis of the laser beam emitted from a semiconductor laser element 1 is tilted by a prescribed angle on semitransmittable reflection surface 27 and a semiconductor substrate 22. At the same time, a plane transpar ent plate 40 serving as an astigmatism corrector and a sealed window in com mon is arranged in parallel with the substrate 22. The laser beam emitted from the element 1 is reflected by the surface 27 of a prism 26 and travels into a plane vertical to the active layer 4 of the element 1 to pass obliquely the plate 40. Thus the astigmatism of the laser beam emitted from the element 1 is corrected. In such a way, it is possible to obtain an extremely compact semiconductor laser device which the stray light is never made incident on a photodetector for the detection of the RF signal. |
