| 摘要 |
An optical disc with high recording density has a double deflection layer (3) formed between the substrate containing the information pits (2) and a protective layer. The deflection layer has a section (3B) which is of a photomagnetic material, such as a composite of terbium, iron and cobalt sandwiched between layers of zinc sulphide material. In operation, the first deflection level is used for the uneven numbered tracks to polarise the received beam for reading. The second level is used for the even numbered tracks, and uses a second polarising light beam. ADVANTAGE - Avoids complicated mfg. procedures and cross-talk between closely neighbouring tracks. |
