Patent ID: 6544716
Filing Date: 2003-04-08
Classification: B82Y,G11B,Y10S,Y10T

Abstract:
A method of reducing a signal distortion caused by thermal feedback from an optical medium to an optical head in a near-field configuration, comprising:providing at least one testing optical medium which has a recording layer over a substrate in an optical medium that is operable to interact with light to read or write data on said recording layer, and a reflective layer between said recording layer and said substrate of said optical medium to reflect back light transmitted through said recording layer, without transmission through said substrate, wherein said recording layer and said reflective layer are located between a medium surface which receives said light and said substrate, coupling light to said at least one testing optical medium in a near-field coupling configuration to determine a threshold input optical power above which a signal distortion caused by heat generated by absorption of said light in said recording layer towards said medium surface occurs; and forming an optical medium with a similar structure as said testing optical medium and includes a reflective layer between a substrate and a recording layer, where at least one power-mitigating layer is positioned relative to said recording layer between a medium surface and said substrate in said optical medium to mitigate conduction of heat generated by optical absorption in said recording layer towards said medium surface and said at least one power-mitigating layer is designed to make a threshold input optical power above which said signal distortion occurs greater than an input optical power level at which data can be written in or read from said recording layer or the testing optical medium.