| 摘要 |
PURPOSE:To make it possible to regenerate signals stably by equalizing the distribution of the light intensities of beam spots with respect to the scanning direction of pits. CONSTITUTION:The laser light emitted from a semiconductor laser 20 is coupled into an optical waveguide 3 through the edge of the optical waveguide 3. The laser light repeats total reflection at the interface between an air layer 10 and a buffer layer 2, and the light is propagated. The beam spot is projected on an optical disk 5 through an emitting grating coupler 4. The distribution of the light intensities of the beam spots is changed in the orthogonal direction with respect to the advancing direction of a pit 5a. The distribution of the light intensity becomes constant in the advancing direction of the pit 5a. The reflected light from the optical disk 5 is cast into an incident grating coupler 7. The light is split through a beam splitter 8. The light beams repeat the total reflection in the optical waveguide 3, and the light beams are collected into photodetectors 9a and 9b. In this way, regeneration errors due to non- uniformity of the beam spots are eliminated, and the stable signal regeneration can be performed. |
