| abstract |
The present invention is directed to an optical recording medium having a polycarbonate substrate with a groove, a recording layer comprised of a partial mirror of a material selected from Ag, Ta, Ni, Cr, Si, or alloys or oxides thereof, a buffer layer of organic material, a thick reflective layer of Au, Al, Ag, or alloys thereof, and a protective coating. By virtue of the partial mirror, the buffer layer and the thick reflective layer, a Fabry-Perot etalon is created. Information can be written by deformation of one or more of the partial mirror, the buffer layer, the thick reflective layer, or the substrate. The deformation changes or destroys the Fabry-Perot, decreasing in the reflectivity. As deformation effects are used for writing, a non-liquid crystalline high-molecular weight material can be used in the buffer layer. The tracking servo employs the difference in reflected amplitude or phase of the partial mirror/substrate interface within and outside the groove. |