Floating optical head integral with light source and photodetector

摘要

Light from the laser (1) passes through the substrate (2), a first transparent layer (3), a diffraction grating (4), and a second transparent layer (5). The light is focussed by a condenser lens (6) onto a point directly below the lens. A spot of light is formed on an optical storage medium below the condenser lens. The reflected light passes through the condenser lens and second transparent layer and is diffracted by the grating to the light receiving plane of the photodetector. The reflected light passes through the first transparent layer to be received by the photodetector.