Single-sided ablative worm optical disk with multilayer protective

Abstract

A single-sided ablative write-once optical disk is usable without a protective cartridge. The disk includes the conventional radiation-transparent polycarbonate substrate that has one surface serving as the disk outer face and an opposite surface that supports the fluorinated hydrocarbon subbing layer and the tellurium-based active data layer. The tellurium alloy in the data layer flows to form holes when subjected to incident laser radiation through the substrate. A multilayer protective coating is formed over the tellurium-based layer and has an outer surface that serves as the other outer face for the disk. The multilayer protective coating includes a deformable layer formed directly on the tellurium-based layer and a scratch-resistant hardcoat formed on the deformable layer. The deformable layer has sufficient hardness and modulus of elasticity to permit the tellurium alloy to flow at conventional laser power levels. In one embodiment the deformable layer is a silicone elastomer. In another embodiment the deformable layer is a fluorinated hydrocarbon, and a metal layer, such as an aluminum-chromium alloy, is formed between the deformable layer and the hardcoat.