Optical information carrier comprising thermochromic or photochromic material

Abstract

The present invention relates to an optical information carrier for recording information by means of an optical beam, said optical information carrier comprising a substrate layer (S), a recording layer (P) including a thermochromic material having temperature-dependent optical characteristics or a photochromic material having light dependent optical characteristics for selectively improving the sensitivity during recording and/or read-out, and a cover layer (C). To achieve an increase reflectivity the recording layer (P) at elevated temperature or high light intensity, respectively, and a very high transmission and low reflectivity at ambient temperature or low light intensity, respectively, it is proposed to use a thermochromic or photochromic material that has an imaginary part k of the complex refractive index ñ being larger than 0 at elevated temperature or high light intensity, respectively. The present invention relates also to a method of determining the thickness of a recording layer of such an optical information carrier and to a read-out device for reading data from such an optical information carrier.

Dependencies are inferred from the claim text.