Magneto-optical recording medium and writing and readout method therefor

摘要

A magneto-optical recording medium having a writing layer formed on a transparent substrate provided with a groove having a flat bottom surface and a flat land, so that writing or readout is carried out on either the groove or the land only by irradiating a laser beam from the substrate side, wherein the sum ( alpha + beta ) of a phase shift alpha of a reflected light of a readout beam by the substrate and a phase shift beta thereof by a layer structure on the transparent substrate, is made to have an opposite sign to a phase shift gamma by interference of reflected lights from the groove and the land.