Method and Apparatus for Multiplexing Optical Information for Recording and Reproducing Optical Information Over Optical Storage Medium

Abstract

There is provided an optical multiplexer including: a substrate having a plurality of beam transmitting portions; and diffraction gratings diffracting beams irradiated to the beam transmitting portions at different angles, each diffraction grating being formed in the corresponding beam transmitting portion. Accordingly, it is possible to reduce an alignment error and manufacturing cost and to reduce the entire size of a recording apparatus or a reproducing apparatus.

What is claimed is: 
     
         1 . An optical multiplexer comprising:
 a substrate having a plurality of beam transmitting portions; and   a plurality of beam transmitting portions formed in and extended through holes in the substrate from the first surface to the second surface, each of the plurality of beam transmitting portions having a diffraction grating, said diffraction grating formed by irradiating a spherical wave beam and a plane wave beam respectively to the each of the plurality of beam transmitting portions, wherein each irradiation angle formed by the spherical beam and the plane wave beam onto each of the beam transmitting portions is different, and the diffraction grating diffracts a beam irradiated to the each of the plurality of beam transmitting portions at different angle, and the diffracted beam is multiplexed, wherein the multiplexed beam is incident on an optical information storage medium to record and reproduce data.