| 摘要 |
PURPOSE:To reduce the manufacturing cost by guiding in turn a laser beam emitted from a laser element on a semiconductor substrate to one pair of detectors formed in the substrate via a prism provided on the substrate. CONSTITUTION:The 1st and 2nd photo detectors 32 and 33 are disposed in the semiconductor substrate 31, and the semiconductor laser element 34 is soldered with pewter 35 on an upper surface 31a of the substrate 31. The upper surface except the section where the pewter 35 is disposed is covered with a protective film 41, and a semitransparent film 42 is provided to cover a corresponding section to the photo detector 32. A prism 36 is provided via an adhesive layer 43 of an epoxy resin. The laser light beam Li' emitted from the laser 34 is reflected by a semitransparent film reflecting surface 36a of the prism 36 and incident upon an optical disk, while a reflected laser beam Lr' from the disk is transmitted through the surface 36a. The beam Lr' is transmitted through the layer 43 and the films 42 and 41 to be incident upon the photo detector 32, and then reflected by an interface between the films 42 and 41 and also the upper surface 36c of the prism to be incident upon the photo detector 33. |
