| 摘要 |
PURPOSE:To improve the recording density of an optical recording means by converging t he spot diameter of a semiconductor laser for an optical pickup to the smallest spot diameter. CONSTITUTION:A phase shifting means having a phase shifting part is arranged on the optical path of a semiconductor laser 1. Conssequently, by reducing and converging the spot diameter of the transmitted light through the phase shifting part to the diameter smaller than that of the light transmitted through an ordinary slit or a minute aperture, recording/reproducing of a signal finely formed is enabled. |
