| 摘要 |
PURPOSE:To considerably reduce the spot diameter of laser beams on a focal plane as compared with the conventional diameter without varying the numerical aperture of a condensing optical system or the wavelength of the laser beams. CONSTITUTION:In order to reduce the spot diameter of laser beams (a) for reproduction on a focal plane determined by the wavelength of the laser beams (a) and the characteristics of a condensing optical system (b) such as a condenser, a nonlinear light absorbing layer (c) is interposed between the recording layer (d) of an optical recording medium and the exit lens surface. At this time, one side of the light absorbing layer (c) is made to coincide with the focal plane. |
