| 摘要 |
PURPOSE:To improve the degree of modulation by providing a beam splitter between an optical recording medium and a laser diode and detecting reflected light obtained through the beam splitter. CONSTITUTION:A laser light beam from the end face 11a of a laser diode 11 is reflected by the optical recording medium 20 through a lens 12, the beam splitter 13 and a lens 14. A part of the reflected light is separated by the beam splitter 13 through the lens 14 and enters a photodetector 16 through a lens 15. By detecting the change of the intensity of the separated light, the presence or absence of the pit of the optical recording medium 20 is read. Meanwhile, the rest of the light which passes through the beam splitter 13 is fed back to the end face 11a of the laser diode 11 through the lens 12. Self combining effect is generated in the laser diode 11 with the light which is fed back and the light output of the laser diode is increased. Thus, the degree of modulation is improved. |
