Design and Fabrication of Thin-Film Diarylethene Recording Layer and Its Reflective Reproduction for Super-Multilayered Optical Memories

We studied the feasibility of two-photon absorption recording and reflective reproduction for three-dimensional (3D) optical memories by comparison between bulk and super-multilayered media. The basic design of such a super-multilayered structure for achieving a high reflectance from a pit and for reducing layer thickness was described. To evaluate basic optical characteristics, two types of sample with a 100% diarylethene recording layer were fabricated. It was experimentally confirmed that reflective reproduction can be possible in the super-multilayered structure, whereas reflective signals were not obtained in the bulk structure as indicated by the results of theoretical analysis. Therefore, 3D recording and reproducing in a super-multilayered medium would be promising for a future high-capacity memory system.