OPTICAL COMPONENT FOR LASER BEAM

摘要

In an optical head apparatus which uses a light source including a blue semiconductor laser, durability deterioration is suppressed for using an optical component composed of an optimized material to be used in an optical path of a laser beam for performing reproduction and recording from and on a CD and CVD. A first transparent substrate (1) and a second transparent substrate (2) sandwich an uneven section (5) composed of a polymer liquid crystal, a filling adhesive (7) for filling the unevenness, and a phase plate (6) having a retardation equivalent to 1/4 of a wavelength used. On the entire surface on the side opposite to the uneven section (5) on the first transparent substrate (1), an inorganic optical multilayer film (3) is formed, and on the entire surface on the side opposite to the uneven section (5) on the second transparent substrate (2), an inorganic optical multilayer film (4) is formed. The intensity of a beam of 400-410nm which enters the second transparent substrate (2) is reduced to 20% or less of the intensity of a beam which enters the optical multilayer film (4) by forming the optical multilayer film.