Optical recording medium

Abstract

In a phase change-type optical recording medium of absorption coefficient control structure used by land/groove recording system, difference in reproduction characteristics between the land and the groove is minimized while ensuring sufficient output of the tracking signal. In the optical recording medium of the present invention, light absorption coefficient at the wavelength of said recording/reproducing beam is such that: Ac/Aa≧0.8 when light absorption coefficient in crystalline region is Ac and light absorption coefficient in amorphous region is Aa; relation between groove width WG and land width WL is such that: 0.97≦2WG/(WL+WG)<1.03; and the relation: λmini≦λu<λmaxi+1, and 12<tR<20 are satisfied when the wavelength of a local minimum in reflectance spectrum is λmini; the wavelength of the local maximum in the reflectance spectrum nearest to the λmini in the wavelength range longer than the λmini is λmaxi+1; said recording/reproducing beam has a wavelength of λu; and said recording layer has a thickness of tR (nm).

Dependencies are inferred from the claim text.