Optisk registreringsmedium basert pÕ Fabry-Perot-prinsipp

摘要

The present invention is in the field of optical recording media, and is directed to an optical recording medium which comprises the following layers; a) a grooved transparent substrate (1), superposed by b) a recording layer comprising a partial mirror (2) of a material having a high complex index of refraction which is not within the pentagon defined by the vertices 7.15 - i3.93, 7.15 - i5.85, 8.96 - 6.28, 9.56 - i5.90, and 8.14 - i3.77 in the n,k plane, superposed by a buffer layer (3) comprising a nonliquid-crystalline high-molecular weight material and optionally a dye, superposed by a thick reflective layer (4), together forming a Fabry-Perot wherein the thickness (d) of the buffer layer within the grooves is set so that the reflection of the medium is in the high reflective state, optionally superposed by c) a protective coating (5). 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 effects change or destroy the Fabry-Perot, and a decrease in reflection is created. As deformation effects are used for writing, a non-liquid crystalline high-molecular weight material can be used in the buffer layer. The tracking (keeping the writing laser within the grooves) can take place by employing the difference in reflected amplitude or phase of the partial mirror/substrate interface within and outside the groove.