SEMICONDUCTOR LASER AND OPTICAL PRINTING DEVICE USING THAT

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor laser, which can conduct stably a control of a printing dot diameter based on a light output modulation when an optical printing is carried out. SOLUTION: A semiconductor laser has two layers of semiconductor layers, which have conductivity types different from each other, an active layer, which is held between the two layers of these semiconductor layers and consists of a semiconductor layer having a forbidden band width narrower than that of the two layers of these semiconductor layers, and a waveguide for confining light within the plane parallel to the active layer and the waveguide is constituted of a narrow region 113 and a wide region 114 for controlling the form of a beam on a laser end face. A region of the intermediate width between the width of the region 113 and the width of the region 114 may be provided between the regions 113 and 114.