Laser optical memory system having beam combining and separating apparatus for combining and separating reading and writing laser beams

摘要

An optical memory system is disclosed employing laser beams for reading and writing data in an optical disk. The system incorporates a specially designed spatial combining and separating device which functions to combine a writing laser beam with a plurality of reading laser beams in a manner so as to permit the combined beams to be precisely focused on the disk. The spatial combining and separating device also functions to separate the reading laser beams from the writing laser beam after they are reflected from the disk in a manner so as to prevent the higher intensity writing beam from interfering with the proper detection of the lower intensity reading beams.