Super-resolution optical disk reader and reading method optimised by measuring reflectivity

摘要

The reader has a reading laser reading an optical disk that comprises a substrate with physical marks. An indium antimonide or gallium antimonide layer is inserted between dielectric layers of a zinc sulfide and silicon oxide compound on the marks. A calculating unit determines critical power located at an intersection point of straight lines joining reflectivity measurements for four power levels, respectively and desirable reading power above the critical power. An application unit applies the reading power for subsequently reading information present on the optical disk. An independent claim is also included for a method for reading an optical disk using a reading laser.