| 摘要 |
PROBLEM TO BE SOLVED: To reduce the diameter of a beam spot without using a floating head by providing the film, which forms the solid immersion lens(SIL) that reduces the diameter of a laser beam spot during the irradiation of the laser beams, on the laser beam irradiation side of a recording film. SOLUTION: On a substrate 1, which is made of polycarbonate, a reflection film 2, a protective film 3, a recording film 4, a protective film 5, an ultraresolution film 6 and an SIL film 7 are successively formed. The film 2 is an Al alloy film with a thickness of 200 nm. The film 3 is a ZnS-SiO2 film having a thickness of 20 nm. The film 4 is a phase transition film made of Ge2 Sb2 Te5 with a thickness of 20 nm. The film 5 is a 100 nm thickness ZnO-SiO2 film. The film 6 is a photodiscoloring film made of water-soluble diazonium salt having a thickness of 100 nm. The film 7 is a 100 nm thickness resin having an apporximate refractive index of 1.8. A magneto-optical film is applicable for the film 4. Thus, a high density recording is made possible by using a magneto-optical disk on which a magnetic ultraresolution technology is used. |
