| 摘要 |
PURPOSE: To prevent the generation of lowering of light quantity and deterioration of a spot shape and to enable excellent and stable recording/reproduction by making a P-polarizing light beam incident on a total reflection optical element having a reflection surface whose outer face is fitted with a protection film. CONSTITUTION: A P-polarizing light beam by a semiconductor laser 1 is made incident on a parallel shift prism 18 of a total reflection element having a total reflection surface fitted with a protection film, reflected by the total reflection surface, made incident on a movable head part 10 and a disk, etc., irradiate them. By this constitution. The deterioration of the characteristic of the total reflection surface of the prism due to the secular change, etc., is prevented by the protection film, the decrease of the light quantity and the deterioration of the shape of a light spot are prevented since the P-polarization is utilized and stable and excellent recording/reproduction is performed. |
