Optical pickup and servo control system for digital data storage

摘要

Methods and apparatus are provided for retrieving encoded information from data tracks on an optical disk using an array of microlasers as the illumination sources, an array of micro-scale photo detectors as the detection elements, and a bilens (BL) or a holographic optical element (HOE) as the main optical component. Multiple configurations are provided to position microlasers and photo detectors together on a mobile laser/detector block (LDB). The microlasers and detectors may be arranged in a hexagonal lattice relationship for an optimally compact arrangement. Laser beams generated by the surface-emitting microlasers are guided by the BL onto the optical disk (OD) surface. The reflected light is collected by the same BL or HOE, shifted, and then directed back onto the respective photo detectors on the LDB. Illumination, detection and alignment methods and apparatus for tracking, focusing, and magnification servo controls are also incorporated on the LDB.