| 摘要 |
PURPOSE:To facilitate the convergence into a minute beam spot by providing a couple of converging elements whose light collection directions are set in orthogonal directions to each other onto a radiation light axis from a semiconductor laser. CONSTITUTION:A couple of planer converging elements 36, 37 are provided on the radiation optical axis (x direction) of a laser beam from a semiconductor laser 35. The converging directions of the elements 36, 37 are set so that the converging directions are made orthogonal to each other. In combining two elements 36, 37 whose light converging direction differ by 90 deg. in this way, collimated beams as to both y, z directions are attained. Thus, the collimate processing and beam shaping processing to the laser beam radiated from the laser 35 are applied at the same time. Thus, the luminous flux to the objective lens is made circular and the light is converged into a minute spot onto an optical disk by using the objective lens. |
