OPTICAL HEAD DEVICE AND PRODUCTION METHOD THEREOF

摘要

An optical head device which improves light utilization efficiency and can be economically produced. The device comprises a glass substrate (1) having a surface of a transparent SiON-base thin film with a pattern of dry-etched recesses (2), and a second glass substrate (3) having a polyimide film as an orientation film. The two substrates are joined with epoxy resin (5) in such a manner that their surfaces are opposed to define a sealed space into which liquid crystal (6) is filled by suction, so that an optically anisotropic diffraction grating is formed. A lambda /4 film (7) is laminated on the outer surface of the second glass substrate (3), and the third glass substrate (9) is bonded to the substrate (3) by a photopolymer (8) to form a diffraction device (10), which is interposed between a light source and an optical recording medium.